CN112974731B - Method for preparing single crystal superalloy by repeatedly using solid solution state columnar crystal - Google Patents

Abstract

According to the method for repeatedly using the solid solution state columnar crystal to prepare the single crystal high-temperature alloy, the corundum tube with the same length as the crystal starting section of the spiral crystal selector wax mold is sleeved into the crystal starting section of the spiral crystal selector wax mold, and the gap between the corundum tube and the crystal starting section is filled with the molten wax, so that the probability of chilling to form mixed crystals due to the fact that the single crystal high-temperature alloy enters the gap between the ceramic mold shell and the unmelted single crystal caused by pouring can be effectively avoided; the ceramic refractory slurry is coated outside the part wax mold, the spiral crystal selector wax mold and the corundum tube, so that the refractory performance of the formed ceramic mold shell can be improved. The invention can be smaller than the deviation range of the crystal orientation of the single crystal high-temperature alloy controlled by the crystal selection method at present, and can realize the repeated use of the solid solution columnar crystal to prepare the single crystal, thereby improving the success rate of the single crystal preparation and reducing the control cost of the single crystal orientation.

Description

A method of repeatedly using solid solution columnar crystals to make single crystal superalloys

technical field

The invention relates to the field of nickel-based single crystal manufacturing, in particular to a method for repeatedly using solid solution columnar crystals to manufacture single crystal superalloys.

Background technique

Nickel-based single-crystal superalloy has excellent high-temperature comprehensive properties and is the preferred material for aero-engine turbine blades. Its mechanical properties have significant anisotropy. During the preparation of single-crystal blades, it is necessary to control its <001> direction within a certain range. So that the single crystal blade has a longer service life. At present, the single crystal superalloy is mainly prepared by the selection method and the seed crystal method in industrial production. The grains selected by the beneficiation method have a certain degree of randomness, and usually only the axial deviation between the crystal orientation and the casting can be controlled within 15°. The seed crystal method can achieve precise control of the crystal orientation, but the single crystal needs to be used as a seed crystal when preparing a single crystal by the seed crystal method, which leads to high production cost and difficult process. Miscellaneous crystals are formed in the melting back zone, resulting in a low yield of single crystals, so it is difficult to use on a large scale in industrial production.

In order to further increase the inlet temperature before the turbine and improve the performance of the aero-engine, the content of refractory elements in the single crystal superalloy is gradually increasing, and the structure of the single crystal blade is becoming more and more complex, which leads to the increasing difficulty of single crystal orientation control. To meet the requirements of single crystal orientation control, a more effective, high success rate and low cost method to control the crystal orientation of single crystal superalloys is urgently needed.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a method for repeatedly using solid solution columnar crystals to prepare single crystal superalloys, so as to solve the technical problems of excessive crystal orientation deviation and high preparation cost when preparing single crystal superalloys by the selection method in the prior art.

The technical scheme of the present invention is: the method comprises the following steps:

The first step is to prepare the wax mold of the spiral separator, melt the wax material at a temperature of 60~100 ℃ and inject it into the mold of the part, and press it under the pressure of 0.5~8MPa to obtain the wax mold of the part; After being melted at a temperature of 60~100°C, it is injected into the spiral separator mold, and pressed under the pressure of 0.5~8MPa to obtain the spiral separator wax mold; the spiral separator wax mold includes a spiral section and a starter Two parts of the crystal segment;

In the second step, the corundum tube with the same length as the crystallizing section of the spiral separator wax mold is sleeved into the crystallizing section of the spiral separator wax mold, and the corundum tube and the spiral separator wax mold are filled with molten wax for crystallizing. The gap between the sections; Weld the part wax mold with one end of the spiral section of the spiral separator wax mold; Apply ceramic refractory slurry on the outside of the part wax mold, the spiral separator wax mold and the corundum tube, and then 100 Dewaxing at a temperature of ~200 °C, and calcining at a temperature of 800~1300 °C for 2~10 hours to obtain a ceramic mold shell. The ceramic mold shell has a crystal opening section, a crystal selection section and a part section;

In the third step, the columnar crystal test block is subjected to solution treatment, and the directionally solidified superalloy body is put into a heat treatment furnace for heat preservation by a one-step solution heat treatment method, and then cooled to obtain a solid solution columnar crystal test block;

The fourth step is to prepare solid solution columnar crystals, cut a test block along the solidification direction on the directionally solidified superalloy body, and grind the surface of the test block with a grinding tool to obtain solid solution columnar crystals; the solid solution The shape of the state columnar crystal is cylindrical; the height of the solid solution state columnar crystal is 20~50mm, and the diameter is 4~20mm;

The fifth step is to prepare a single crystal superalloy casting, and insert the solid solution columnar crystal into the crystal opening section of the ceramic mold shell; put the solid solution columnar crystal and the ceramic mold shell into the single crystal furnace together, and adjust the inside of the single crystal furnace The temperature reaches 1400~1600°C, and the temperature is kept for 1~15min; the superalloy metal liquid is poured into the ceramic mold shell, and the temperature is kept for 1~15min; the crystal is moved downward; That is, the first single crystal superalloy casting is obtained;

The sixth step is to recover the reused columnar crystals, remove the mold shell of the obtained single crystal superalloy test rod; disconnect the obtained first single crystal superalloy casting from the boundary between the crystal selection section and the crystal opening section, so that the Said crystal-opening segment is recovered as a reusable columnar crystal;

In the seventh step, the recovered columnar crystals are subjected to solid solution treatment again, and the columnar crystals recovered in the sixth step are again subjected to the third step of solid solution treatment, and the treated solid solution columnar crystal test block is the recovered solid solution columnar crystal. crystal;

The eighth step, grinding the recovered solid solution columnar crystals; grinding the surface of the recovered solid solution columnar crystals with a grinding tool to obtain reusable columnar crystals;

In the ninth step, the remaining single crystal superalloy castings are prepared, and the reusable solid solution columnar crystals in the eighth step are used to continue to prepare single crystal superalloy castings; the reusable solid solution columnar crystals are stuffed into the second step. The obtained ceramic mold shell opens the crystal section; the solid solution columnar crystal and the ceramic mold shell are put into the single crystal furnace together, the temperature in the single crystal furnace is adjusted to 1400~1600 ℃, and the temperature is kept for 1~15min; Pouring into a ceramic mold shell, keeping the temperature for 1-15 minutes; moving the crystal downward; after the crystal pulling is completed, it is cooled to room temperature with the furnace and taken out, that is, a second single crystal superalloy casting is obtained; the superalloy metal liquid The temperature is 1400~1800℃.

Further, in the second step, a corundum tube is used as the inner wall of the crystal-opening section of the ceramic mold shell.

Further, in the second step, the thickness of the ceramic refractory slurry is 1-10 mm coated on the outside of the wax mold of the part, the wax mold of the spiral separator and the corundum tube.

Further, in the third step, the temperature of the heat treatment furnace is 1100°C to 1450°C, and the temperature is kept for 2h-10h.

Further, in the fifth step, the temperature of the superalloy metal liquid is 1400-1800°C.

Further, in the fifth step, the gap between the solid solution columnar crystal and the inner wall of the crystal opening section of the ceramic mold shell is between 0.01 and 0.5 mm.

Further, in the ninth step, the gap between the solid solution columnar crystal and the inner wall of the crystal opening section of the ceramic mold shell is between 0.01 and 0.5 mm.

Further, in the fifth step, the speed of moving the crystal downward is 0.1-9 mm/min.

Further, in the ninth step, the speed of moving the crystal downward is 0.1-15 mm/min.

Further, in the fourth step and the eighth step, the grinding tool is 80#, 320#, 600# or 1000# sandpaper.

The present invention provides a method for repeatedly using solid solution columnar crystals to make single crystal superalloys by improving, and compared with the prior art, it has the following improvements and advantages:

First, the purpose of the present invention is to repeatedly use the solid solution columnar crystals combined with the selection method to prepare single crystal superalloys, and the deviation of the crystal <001> direction from the directional solidification direction can be controlled within 5 degrees, which can be smaller than the current use of the selection method. The method can control the deviation range of the crystal orientation of the single crystal superalloy, and can realize the repeated use of solid solution columnar crystals to prepare single crystals, improve the success rate of single crystal preparation, and reduce the cost of single crystal orientation control.

Second, in the present invention, the corundum tube having the same length as the crystallizing section of the wax mold of the spiral separator is sleeved into the crystallizing section of the wax mold of the spiral separator, and the molten wax material is used to fill the gap between the corundum tube and the crystallizing section. The gap can effectively avoid the chance of the single crystal superalloy entering the gap between the ceramic mold shell and the unmelted single crystal due to casting, resulting in the formation of miscellaneous crystals by chilling; coating on the exterior of the wax mold of the part, the wax mold of the spiral separator and the corundum tube The ceramic refractory slurry can improve the refractory performance of the formed ceramic mold shell.

Description of drawings

Below in conjunction with accompanying drawing and embodiment, the present invention is further explained:

Fig. 1 is a schematic diagram of a ceramic mold shell structure;

Fig. 2 is a schematic diagram of the assembly of a solid solution columnar crystal mold shell;

Figure 3 is a metallographic diagram of a single crystal superalloy prepared by this method.

Description of reference numbers:

1. Crystal opening section of ceramic mold shell; 2. Crystal selection section of ceramic mold shell; 3. Parts section of ceramic mold shell; 4. Corundum tube; 5. Columnar crystal.

Detailed ways

The present invention will be described in detail below with reference to Fig. 1 to Fig. 3, and the technical solutions in the embodiments of the present invention will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the implementations. example. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

The present invention provides a method for repeatedly using solid solution columnar crystals to manufacture single crystal superalloys by improving, as shown in Figures 1 to 3:

Example 1:

The specific steps of preparing Ni-14Mo-7Al single crystal superalloy bar are as follows:

The first step is to prepare the wax mold of the spiral separator, melt the wax material at a temperature of 75 ° C and inject it into the mold of the part, and press it under the pressure of 0.5 MPa to obtain the wax mold of the part; put the wax material at 75 ° C. After being melted at a low temperature, it is injected into the spiral separator mold, and pressed and formed under the pressure of 0.5MPa to obtain the spiral separator wax mold; the above-mentioned spiral separator wax mold includes two parts: a spiral section and a crystal opening section;

In the second step, the corundum tube with the same length as the crystallizing section of the spiral separator wax mold is sleeved into the crystallizing section of the spiral separator wax mold, and the corundum tube and the spiral separator wax mold are filled with molten wax for crystallizing. The gap between the sections; Weld the part wax mold with one end of the spiral section of the spiral separator wax mold; apply 100mm ceramic refractory slurry on the outside of the part wax mold, the spiral separator wax mold and the corundum tube, and then apply Dewaxing at a temperature of 150°C, and firing at 1000°C for 10 hours to obtain a ceramic mold shell. Corresponding to the structure of the wax mold, the ceramic mold shell has a crystal opening section, a crystal selection section and a part section. Corundum tube is the inner wall;

In the third step, the columnar crystal test block is subjected to solution treatment, and the directionally solidified Ni-14Mo-7Al superalloy body is placed in a heat treatment furnace at 1395 ° C for 2 hours by a one-step solution heat treatment method, and then cooled to obtain Solid solution columnar crystal test block;

The fourth step is to prepare solid solution columnar crystals, cut a test block along the solidification direction on the directionally solidified superalloy body, and grind the surface of the test block with 80#, 320#, 600# or 1000# sandpaper to obtain The solid solution columnar crystal; the shape of the solid solution columnar crystal is cylindrical; the solid solution columnar crystal is 20mm in height and 20mm in diameter;

The fifth step is to prepare a single crystal superalloy casting, and insert the solid solution columnar crystal into the crystal opening section of the ceramic mold shell, and the gap between the solid solution columnar crystal and the inner wall of the crystal opening section of the mold shell is between 0.5mm; The solid solution columnar crystal and the ceramic mold shell are put into the single crystal furnace together, the temperature in the single crystal furnace is adjusted to 1580 °C, and the temperature is kept for 1 min; Move the crystal downward at a speed of min to pull the crystal; after the crystal pulling is completed, it is cooled to room temperature with the furnace and taken out, that is, the first single crystal superalloy casting is obtained, and the temperature of the superalloy metal liquid is 1400 ° C.

The sixth step is to recover the reused columnar crystals, remove the mold shell of the obtained single crystal superalloy test rod; disconnect the obtained first single crystal superalloy casting from the boundary between the crystal selection section and the crystal opening section, so that the Said crystal-opening segment is recovered as a reusable columnar crystal;

In the seventh step, the recovered columnar crystals are solution-treated again, and the columnar crystals recovered in the sixth step are put into a heat treatment furnace with a temperature of 1395° C. for 2 hours by adopting a one-step solution heat treatment method, and then cooled to obtain a solid solution. The columnar crystal test block in solution state; the columnar crystal test block in solid solution state is the recovered columnar crystal in solid solution state;

The eighth step, grinding the recovered solid solution columnar crystals; using 80#, 320#, 600# or 1000# sandpaper to grind the surface of the recovered solid solution columnar crystals to obtain reusable columnar crystals;

In the ninth step, the remaining single crystal superalloy castings are prepared, and the reusable solid solution columnar crystals in the eighth step are used to continue to prepare single crystal superalloy castings; the reusable solid solution columnar crystals are stuffed into the second step. The gap between the reusable solid-solution columnar crystal and the inner wall of the crystal-opening section of the obtained ceramic mold shell is 0.2mm; the solid solution columnar crystal and the ceramic mold shell are put into the single crystal together In the furnace, adjust the temperature in the single crystal furnace to 1580°C, and keep it for 1min; pour the superalloy metal liquid into the ceramic mold shell, and keep it for 15min; move the crystal downward at a speed of 3mm/min; The second single crystal superalloy casting is obtained after being cooled to room temperature with the furnace; the temperature of the superalloy metal liquid is 1400°C;

Repeat the sixth to ninth steps, continue to recover the reusable solid solution columnar crystals on the new single crystal superalloy casting, and use the obtained reusable solid solution columnar crystals to prepare the remaining single crystal superalloys Castings until the desired number of single crystal superalloy castings are obtained.

Example 2:

To prepare Ni-13.5Mo-7.6 Al-0.05B single crystal superalloy rod, the specific steps are:

The first step is to prepare the wax mold of the spiral separator, melt the wax material at a temperature of 100 ° C and inject it into the mold of the part, and press it under the pressure of 8 MPa to obtain the wax mold of the part; put the wax material at 100 ° C. After being melted at the temperature, it is injected into the spiral separator mold, and pressed and formed under the pressure of 8MPa to obtain the spiral separator wax mold; the above-mentioned spiral separator wax mold includes two parts: a spiral section and a crystal opening section;

In the second step, the corundum tube with the same length as the crystallizing section of the spiral separator wax mold is sleeved into the crystallizing section of the spiral separator wax mold, and the corundum tube and the spiral separator wax mold are filled with molten wax for crystallizing. The gap between the segments; Weld the part wax mold with one end of the spiral section of the spiral separator wax mold; apply 1mm ceramic refractory slurry on the outside of the part wax mold, the spiral separator wax mold and the corundum tube, and then apply Dewaxing at a temperature of 200 °C, and calcining at a temperature of 1300 °C for 2 hours to obtain a ceramic mold shell. Corresponding to the structure of the wax mold, the ceramic mold shell has a crystal opening section, a crystal selection section and a part section. The crystal opening section of the mold shell is made of corundum. The tube is the inner wall;

In the third step, the columnar crystal test block is subjected to solution treatment, and the directional solidification Ni-13.5Mo-7.6 Al-0.05B superalloy body is placed in a heat treatment furnace at 1100 ° C for 10 hours by a one-step solution heat treatment method. Then, it is cooled to obtain a solid solution columnar crystal test block;

The fourth step is to prepare solid solution columnar crystals, cut a test block along the solidification direction on the directionally solidified superalloy body, and grind the surface of the test block with 80#, 320#, 600# or 1000# sandpaper to obtain The solid solution columnar crystal; the shape of the solid solution columnar crystal is cylindrical; the solid solution columnar crystal is 50mm in height and 4mm in diameter;

The fifth step is to prepare a single crystal superalloy casting, insert the solid solution columnar crystal into the crystal opening section of the ceramic mold, and the gap between the solid solution columnar crystal and the inner wall of the crystal opening section of the mold shell is between 0.01mm; The solid solution columnar crystal and the ceramic mold shell are put into the single crystal furnace together, the temperature in the single crystal furnace is adjusted to 1400 ℃, and the temperature is kept for 5 minutes; Move the crystal downward at a speed of /min; after the crystal pulling is completed, cool down to room temperature with the furnace and take it out to obtain the first single crystal superalloy casting, and the temperature of the superalloy metal liquid is 1800°C.

The sixth step is to recover the reused columnar crystals, remove the mold shell of the obtained single crystal superalloy test rod; disconnect the obtained first single crystal superalloy casting from the boundary between the crystal selection section and the crystal opening section, so that the Said crystal-opening segment is recovered as a reusable columnar crystal;

In the seventh step, the recovered columnar crystals are solution-treated again, and a one-step solution heat treatment method is adopted. The columnar crystal test block in solution state; the columnar crystal test block in solid solution state is the recovered columnar crystal in solid solution state;

The eighth step, grinding the recovered solid solution columnar crystals; using 80#, 320#, 600# or 1000# sandpaper to grind the surface of the recovered solid solution columnar crystals to obtain reusable columnar crystals;

In the ninth step, the remaining single crystal superalloy castings are prepared, and the reusable solid solution columnar crystals in the eighth step are used to continue to prepare single crystal superalloy castings; the reusable solid solution columnar crystals are stuffed into the second step. The gap between the reusable solid solution columnar crystal and the inner wall of the crystal opening section of the obtained ceramic mold shell is 0.03mm; the solid solution columnar crystal and the ceramic mold shell are put into the single crystal together In the furnace, adjust the temperature in the single crystal furnace to 1400°C, and keep it for 5 minutes; pour the superalloy metal liquid into the ceramic mold shell, and keep it for 10 minutes; move the crystal downward at a speed of 0.1mm/min; , take it out after being cooled to room temperature with the furnace, that is, a second single crystal superalloy casting is obtained; the temperature of the superalloy metal liquid is 1400°C;

Repeat the sixth to ninth steps, continue to recover the reusable solid solution columnar crystals on the new single crystal superalloy casting, and use the obtained reusable solid solution columnar crystals to prepare the remaining single crystal superalloys Castings until the desired number of single crystal superalloy castings are obtained.

Example 3:

To prepare Ni-12Mo-7.2 Al-0.02B single crystal superalloy castings, the specific steps are:

The first step is to prepare the wax mold of the spiral separator, melt the wax material at a temperature of 80 ° C and inject it into the mold of the part, and press it under the pressure of 5 MPa to obtain the wax mold of the part; put the wax material at 80 ° C. After being melted at the temperature, it is injected into the spiral separator mold, and pressed and formed under the pressure of 5MPa to obtain the spiral separator wax mold; the above-mentioned spiral separator wax mold includes two parts: a spiral section and a crystal opening section;

In the second step, the corundum tube with the same length as the crystallizing section of the spiral separator wax mold is sleeved into the crystallizing section of the spiral separator wax mold, and the corundum tube and the spiral separator wax mold are filled with molten wax for crystallizing. The gap between the sections; weld the part wax mold to one end of the spiral section of the spiral separator wax mold; apply 5mm ceramic refractory slurry on the outside of the part wax mold, the spiral separator wax mold and the corundum tube, and then Dewaxing at 200°C, and calcining at 800°C for 3 hours to obtain a ceramic mold shell. Corresponding to the structure of the wax mold, the ceramic mold shell has a crystal opening section, a crystal selection section and a part section. Corundum tube is the inner wall;

In the third step, the columnar crystal test block is subjected to solution treatment, and the directional solidification Ni-12Mo-7.2 Al-0.02B superalloy body is placed in a heat treatment furnace at 1250 ° C for 6 hours by means of one-step solution heat treatment. Cooling to obtain a solid solution columnar crystal test block;

The fourth step is to prepare solid solution columnar crystals, cut a test block along the solidification direction on the directionally solidified superalloy body, and grind the surface of the test block with 80#, 320#, 600# or 1000# sandpaper to obtain The solid solution columnar crystal; the shape of the solid solution columnar crystal is cylindrical; the solid solution columnar crystal is 30mm in height and 10mm in diameter;

The fifth step is to prepare a single crystal superalloy casting, plug the solid solution columnar crystal into the crystal opening section of the ceramic mold, and the gap between the solid solution columnar crystal and the inner wall of the crystal opening section of the mold shell is between 0.1mm; The solid solution columnar crystal and the ceramic mold shell are put into the single crystal furnace together, the temperature in the single crystal furnace is adjusted to 1600 °C, and the temperature is kept for 15 minutes; Move the crystal downward at the speed of min to pull the crystal; after the crystal pulling is completed, the furnace is cooled to room temperature and taken out to obtain the first single crystal superalloy casting, and the temperature of the superalloy metal liquid is 1500°C.

The sixth step is to recover the reused columnar crystals, remove the mold shell of the obtained single crystal superalloy test rod; disconnect the obtained first single crystal superalloy casting from the boundary between the crystal selection section and the crystal opening section, so that the Said crystal-opening segment is recovered as a reusable columnar crystal;

In the seventh step, the recovered columnar crystals are solution-treated again, and a one-step solution heat treatment method is adopted. The columnar crystal test block in solution state; the columnar crystal test block in solid solution state is the recovered columnar crystal in solid solution state;

The eighth step, grinding the recovered solid solution columnar crystals; using 80#, 320#, 600# or 1000# sandpaper to grind the surface of the recovered solid solution columnar crystals to obtain reusable columnar crystals;

In the ninth step, the remaining single crystal superalloy castings are prepared, and the reusable solid solution columnar crystals in the eighth step are used to continue to prepare single crystal superalloy castings; the reusable solid solution columnar crystals are stuffed into the second step. The gap between the reusable solid-solution columnar crystal and the inner wall of the crystal-opening section of the obtained ceramic mold shell is 0.15mm; the solid-solution columnar crystal and the ceramic mold shell are put into the single crystal together In the furnace, adjust the temperature in the single crystal furnace to 1600 ℃, and keep it for 30 minutes; pour the superalloy metal liquid into the ceramic mold shell, and keep it for 20 minutes; move the crystal downward at a speed of 9mm/min; The second single crystal superalloy casting is obtained after being cooled to room temperature in the furnace; the temperature of the superalloy metal liquid is 1500°C;

Repeat the sixth to ninth steps, continue to recover the reusable solid solution columnar crystals on the new single crystal superalloy casting, and use the obtained reusable solid solution columnar crystals to prepare the remaining single crystal superalloys Castings until the desired number of single crystal superalloy castings are obtained.

Example 4:

To prepare Ni-3.2Cr-1.2Mo-6Al-10Co-6W-4Re-7.98Ta single crystal superalloy castings, the specific steps are:

The first step is to prepare the wax mold of the spiral separator, melt the wax material at a temperature of 60 ° C and inject it into the mold of the part, and press it under the pressure of 5 MPa to obtain the wax mold of the part; put the wax material at 60 ° C. After being melted at the temperature, it is injected into the spiral separator mold, and pressed and formed under the pressure of 5MPa to obtain the spiral separator wax mold; the above-mentioned spiral separator wax mold includes two parts: a spiral section and a crystal opening section;

In the second step, the corundum tube with the same length as the crystallizing section of the spiral separator wax mold is sleeved into the crystallizing section of the spiral separator wax mold, and the corundum tube and the spiral separator wax mold are filled with molten wax for crystallizing. The gap between the segments; Weld the part wax mold with one end of the spiral section of the spiral separator wax mold; apply 7mm ceramic refractory slurry on the outside of the part wax mold, the spiral separator wax mold and the corundum tube, and then apply Dewaxing at a temperature of 100 °C, and calcining at a temperature of 1300 °C for 5 hours to obtain a ceramic mold shell. Corresponding to the structure of the wax mold, the ceramic mold shell has a crystal opening section, a crystal selection section and a part section. Corundum tube is the inner wall;

In the third step, the columnar crystal test block is subjected to solution treatment, and the directionally solidified Ni-3.2Cr-1.2Mo-6Al-10Co-6W-4Re-7.98Ta superalloy body is placed in 1350 ℃ by one-step solution heat treatment. The heat treatment furnace was kept for 6h, and then cooled to obtain a solid solution columnar crystal test block;

The fourth step is to prepare solid solution columnar crystals, cut a test block along the solidification direction on the directionally solidified superalloy body, and grind the surface of the test block with 80#, 320#, 600# or 1000# sandpaper to obtain Solid solution columnar crystal; the shape of the solid solution columnar crystal is cylindrical; the solid solution columnar crystal is 25m in height and 7mm in diameter;

The fifth step is to prepare a single crystal superalloy casting, and insert the solid solution columnar crystal into the crystal opening section of the ceramic mold shell, and the gap between the solid solution state columnar crystal and the inner wall of the crystal opening section of the mold shell is between 0.05mm; The solid solution columnar crystal and the ceramic mold shell are put into the single crystal furnace together, the temperature in the single crystal furnace is adjusted to 1500 ℃, and the temperature is kept for 3 minutes; Move the crystal downward at the speed of min to pull the crystal; after the crystal pulling is completed, the furnace is cooled to room temperature and taken out to obtain the first single crystal superalloy casting, and the temperature of the superalloy metal liquid is 1500°C.

The sixth step is to recover the reused columnar crystals, remove the mold shell of the obtained single crystal superalloy test rod; disconnect the obtained first single crystal superalloy casting from the boundary between the crystal selection section and the crystal opening section, so that the Said crystal-opening segment is recovered as a reusable columnar crystal;

In the seventh step, the recovered columnar crystals are solution-treated again, and a one-step solution heat treatment method is adopted. The columnar crystal test block in solution state; the columnar crystal test block in solid solution state is the recovered columnar crystal in solid solution state;

The eighth step, grinding the recovered solid solution columnar crystals; using 80#, 320#, 600# or 1000# sandpaper to grind the surface of the recovered solid solution columnar crystals to obtain reusable columnar crystals;

In the ninth step, the remaining single crystal superalloy castings are prepared, and the reusable solid solution columnar crystals in the eighth step are used to continue to prepare single crystal superalloy castings; the reusable solid solution columnar crystals are stuffed into the second step. The gap between the reusable solid solution columnar crystal and the inner wall of the crystal opening section of the obtained ceramic mold shell is 0.13mm; the solid solution columnar crystal and the ceramic mold shell are put into the single crystal together In the furnace, adjust the temperature in the single crystal furnace to 1500°C, and keep it for 3 minutes; pour the superalloy metal liquid into the ceramic mold shell and keep it for 5 minutes; move the crystal downward at a speed of 7mm/min; The second single crystal superalloy casting is obtained after being cooled to room temperature in the furnace; the temperature of the superalloy metal liquid is 1500°C;

Repeat the sixth to ninth steps, continue to recover the reusable solid solution columnar crystals on the new single crystal superalloy casting, and use the obtained reusable solid solution columnar crystals to prepare the remaining single crystal superalloys Castings until the desired number of single crystal superalloy castings are obtained.

Example 5:

To prepare Ni-3Cr-1Mo-6Al-11.6Co-6.3W-4.4Re-7.95Ta-1Hf single crystal superalloy castings, the specific steps are:

The first step is to prepare the wax mold of the spiral separator, melt the wax material at a temperature of 90 ° C and inject it into the mold of the part, and press it under the pressure of 2 MPa to obtain the wax mold of the part; put the wax material at 90 ° C. After being melted at the temperature, it is injected into the spiral separator mold, and pressed and formed under the pressure of 2MPa to obtain the spiral separator wax mold; the above-mentioned spiral separator wax mold includes two parts: a spiral section and a crystal opening section;

In the second step, the corundum tube with the same length as the crystallizing section of the spiral separator wax mold is sleeved into the crystallizing section of the spiral separator wax mold, and the corundum tube and the spiral separator wax mold are filled with molten wax for crystallizing. The gap between the segments; Weld the part wax mold with one end of the spiral section of the spiral separator wax mold; apply 6mm ceramic refractory slurry on the outside of the part wax mold, spiral separator wax mold and corundum tube, and then Dewaxing at a temperature of 120°C, and calcining at a temperature of 850°C for 4 hours to obtain a ceramic mold shell. Corresponding to the structure of the wax mold, the ceramic mold shell has a crystal opening section, a crystal selection section and a part section. Corundum tube is the inner wall;

The third step is to perform solution treatment on the columnar crystal test block, and the directional solidification Ni-3Cr-1Mo-6Al-11.6Co-6.3W-4.4Re-7.95Ta-1Hf superalloy body is placed in a one-step solution heat treatment method. Put it into a heat treatment furnace at 1400 °C for 4 hours, and then cool it to obtain a solid solution columnar crystal test block;

The fourth step is to prepare solid solution columnar crystals, cut a test block along the solidification direction on the directionally solidified superalloy body, and grind the surface of the test block with 80#, 320#, 600# or 1000# sandpaper to obtain Solid solution columnar crystal; the shape of the solid solution columnar crystal is cylindrical; the solid solution columnar crystal is 20m in height and 8mm in diameter;

The fifth step is to prepare a single crystal superalloy casting, insert the solid solution columnar crystal into the crystal opening section of the ceramic mold, and the gap between the solid solution columnar crystal and the inner wall of the crystal opening section of the mold shell is between 0.12mm; The solid solution columnar crystal and the ceramic mold shell are put into the single crystal furnace together, the temperature in the single crystal furnace is adjusted to 1580 ℃, and the temperature is kept for 4 minutes; Move the crystal downward at a speed of min to pull the crystal; after the crystal pulling is completed, it is cooled to room temperature with the furnace and taken out, that is, the first single crystal superalloy casting is obtained, and the temperature of the superalloy metal liquid is 1520 ° C.

The sixth step is to recover the reused columnar crystals, remove the mold shell of the obtained single crystal superalloy test rod; disconnect the obtained first single crystal superalloy casting from the boundary between the crystal selection section and the crystal opening section, so that the Said crystal-opening segment is recovered as a reusable columnar crystal;

In the seventh step, the recovered columnar crystals are solution-treated again, and a one-step solution heat treatment method is adopted. The columnar crystal test block in solution state; the columnar crystal test block in solid solution state is the recovered columnar crystal in solid solution state;

The eighth step, grinding the recovered solid solution columnar crystals; using 80#, 320#, 600# or 1000# sandpaper to grind the surface of the recovered solid solution columnar crystals to obtain reusable columnar crystals;

In the ninth step, the remaining single crystal superalloy castings are prepared, and the reusable solid solution columnar crystals in the eighth step are used to continue to prepare single crystal superalloy castings; the reusable solid solution columnar crystals are stuffed into the second step. The gap between the reusable solid-solution columnar crystal and the inner wall of the crystal-opening section of the obtained ceramic mold shell is 0.2mm; the solid solution columnar crystal and the ceramic mold shell are put into the single crystal together In the furnace, adjust the temperature in the single crystal furnace to 1580 ℃, and keep it for 4 minutes; pour the superalloy metal liquid into the ceramic mold shell, and keep it for 4 minutes; move the crystal downward at a speed of 6mm/min; The second single crystal superalloy casting is obtained after cooling to room temperature with the furnace; the temperature of the superalloy metal liquid is 1520°C;

Repeat the sixth to ninth steps, continue to recover the reusable solid solution columnar crystals on the new single crystal superalloy casting, and use the obtained reusable solid solution columnar crystals to prepare the remaining single crystal superalloys Castings until the desired number of single crystal superalloy castings are obtained.

The purpose of the present invention is to repeatedly use the solid solution columnar crystals combined with the crystal selection method to prepare single crystal superalloys, and the deviation of the crystal <001> direction from the directional solidification direction can be controlled within 5 degrees, which is less than the current control of single crystal superalloys by the crystal selection method. The deviation range of the crystal orientation of the superalloy can be realized, and the solid solution columnar crystal can be used repeatedly to prepare single crystals, which can improve the success rate of single crystal preparation and reduce the cost of single crystal orientation control;

The corundum tube with the same length as the crystallizing section of the wax mold of the spiral separator is sleeved into the crystallizing section of the wax mold of the spiral separator, and the gap between the corundum tube and the crystallizing section is filled with molten wax, which can effectively avoid the Casting causes the single crystal superalloy to enter the gap between the ceramic mold shell and the unmelted single crystal, resulting in the probability of quenching and forming miscellaneous crystals; coating ceramic refractory slurry on the outside of the wax mold of the part, the wax mold of the spiral separator and the corundum tube, can Improve the refractory performance of the formed ceramic mold shell.

The above description of the disclosed embodiments enables any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (6)

1. A method for repeatedly using solid solution columnar crystals to make single crystal superalloys, characterized in that, controlling its crystal <001> direction to deviate from the direction of directional solidification within 5 degrees, the method comprising the following steps: The first step is to prepare the wax mold of the part and the wax mold of the spiral crystal selector, melt the wax material and inject it into the mold of the part, and press it to form the wax mold of the part; after the wax material is melted, it is injected into the mold of the spiral crystal selector, and Press molding to obtain a spiral crystal separator wax mold; the above-mentioned spiral crystal separator wax mold includes two parts: a spiral section and a crystal opening section; In the second step, the corundum tube with the same length as the crystallizing section of the spiral separator wax mold is sleeved into the crystallizing section of the spiral separator wax mold, and the corundum tube and the spiral separator wax mold are filled with molten wax for crystallizing. The gap between the segments; Weld the part wax mold with one end of the spiral section of the spiral separator wax mold; Apply ceramic refractory slurry on the outside of the part wax mold, the spiral separator wax mold and the corundum tube, and then in a certain Dewaxing at the temperature, and after firing for a certain period of time, a ceramic mold shell is obtained, and the ceramic mold shell has a crystal opening section, a crystal selection section and a part section; The third step is to perform solid solution treatment on the columnar crystal test block, adopting a one-step solution heat treatment method, placing the directionally solidified superalloy body in a heat treatment furnace for heat preservation, and then cooling to obtain a solid solution columnar crystal test block, heat treatment The temperature of the furnace is 1100℃~1450℃, and the temperature is kept for 2h-10h; The fourth step is to prepare solid solution columnar crystals, cut a test block along the solidification direction on the directionally solidified superalloy body, and grind the surface of the test block with a grinding tool to obtain solid solution columnar crystals. The shape of the state columnar crystal is cylindrical; the height of the solid solution state columnar crystal is 20~50mm, and the diameter is 4~20mm; The fifth step is to prepare a single crystal superalloy casting, and insert the solid solution columnar crystal into the crystal opening section of the ceramic mold shell; put the solid solution columnar crystal and the ceramic mold shell into the single crystal furnace together, and adjust the inside of the single crystal furnace temperature, and keep it for a certain period of time; pour the superalloy metal liquid into the ceramic mold shell, and keep it for a certain period of time; move the crystal downward; after the crystal pulling is completed, cool it to room temperature with the furnace and take it out, that is, the first single piece is obtained. Crystal superalloy castings; The sixth step is to recover the reused columnar crystals, remove the mold shell of the obtained single crystal superalloy test rod; disconnect the obtained first single crystal superalloy casting from the boundary between the crystal selection section and the crystal opening section, so that the Said crystal-opening segment is recovered as a reusable columnar crystal; In the seventh step, the recovered columnar crystals are subjected to solid solution treatment again, and the columnar crystals recovered in the sixth step are again subjected to the third step of solid solution treatment, and the treated solid solution columnar crystal test block is the recovered solid solution columnar crystal. crystal; The eighth step, grinding the recovered solid solution columnar crystals; grinding the surface of the recovered solid solution columnar crystals with a grinding tool to obtain reusable columnar crystals; In the ninth step, the remaining single crystal superalloy castings are prepared, and the reusable solid solution columnar crystals in the eighth step are used to continue to prepare single crystal superalloy castings; the reusable solid solution columnar crystals are stuffed into the second step. The obtained ceramic mold shell opens the crystal section; the solid solution columnar crystal and the ceramic mold shell are put into the single crystal furnace together, the temperature in the single crystal furnace is adjusted, and the temperature is kept for a certain period of time, and the superalloy metal liquid is poured into the ceramic mold shell. , after holding for a certain period of time; move the crystal downward; after the crystal pulling is completed, take it out after cooling to room temperature with the furnace, that is, a second single crystal superalloy casting is obtained; in the second step, the ceramic mold shell is crystallized The section takes the corundum tube as the inner wall; In the fifth step, the solid solution columnar crystal and the ceramic mold shell are put into the single crystal furnace together, the temperature in the single crystal furnace is adjusted to 1400~1600°C, and the temperature is kept for 1~15min; the superalloy metal liquid is poured In the ceramic mold shell, after 1~15min of heat preservation, move downward to pull the crystal; the temperature of the superalloy metal liquid is 1400~1800 ℃, and the gap between the solid solution columnar crystal and the inner wall of the crystal opening section of the ceramic mold shell is Between 0.01~0.5mm; In the fifth step, the speed of moving the crystal downward is 7~9mm/min; In the ninth step, the speed of moving the crystal downward is 7-15 mm/min. 2. The method for reusing solid solution columnar crystals to make single crystal superalloys according to claim 1, wherein in the first step, the wax material is melted at a temperature of 60-100°C and then injected into the part The mold is pressed and formed under the pressure of 0.5~8MPa to obtain the wax mold of the part; the wax material is melted at a temperature of 60~100℃ and injected into the spiral separator mold, and pressed under the pressure of 0.5~8MPa Shaped to obtain a spiral separator wax mold. 3. The method for reusing solid solution columnar crystals to make single crystal superalloys as claimed in claim 1, wherein in the second step, dewaxing is performed at a temperature of 100-200° C., and a temperature of 800-1300° C. After calcination at ℃ temperature for 2~10 hours, the ceramic mold shell is obtained, and the thickness of the ceramic refractory slurry is 1~10mm coated on the wax mold of the part, the wax mold of the spiral separator and the corundum tube. 4. The method for repeatedly using solid solution columnar crystals to make single crystal superalloys as claimed in claim 1, wherein in the ninth step, the solid solution columnar crystals and the inner wall of the crystal opening section of the ceramic mold shell are separated from each other. The gap between them is between 0.01~0.5mm. 5. The method for reusing solid solution columnar crystals to make single crystal superalloy as claimed in claim 1, wherein the fourth step to the ninth step is repeated, and the recovery is repeated on the new single crystal superalloy casting. The solid solution columnar crystals are used, and the resulting reusable solid solution columnar crystals are used to prepare the remaining single crystal superalloy castings until the desired number of single crystal superalloy castings are obtained. 6. The method for reusing solid solution columnar crystals to make single crystal superalloys according to claim 1, wherein in the fourth step and the eighth step, the grinding tools are 80#, 320# , 600# or 1000# sandpaper.

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