CN116715529A - Preparation method of irregular symmetrical precise special-shaped ceramic tube for LED (light-emitting diode) electric vacuum packaging - Google Patents

Abstract

A method for preparing an irregularly symmetrical precision special-shaped ceramic tube for LED electric vacuum packaging. The irregularly symmetrical precision special-shaped ceramic tube for LED electric vacuum packaging includes a middle round tube, an irregular symmetrical end, and a tail tube; wherein the middle round tube, The tail pipe is made into an intermediate round tube blank and a tail pipe blank through a screw extrusion process; the irregular symmetrical end is made into an irregular symmetrical end blank by hot-pressing injection molding of an elastic inflatable core; the intermediate round pipe blank and the tail pipe blank are , the irregular symmetrical end blanks are assembled into irregular symmetrical precision special-shaped ceramic tube blanks for LED electric vacuum packaging, and are pre-fired and sintered to make irregular symmetrical precision special-shaped ceramic tubes for LED electric vacuum packaging, thereby solving the problem of LED electric vacuum packaging Technical difficulties in manufacturing irregularly symmetrical precision special-shaped ceramic tubes.

Description

A method for preparing irregularly symmetrical precision special-shaped ceramic tubes for LED electric vacuum packaging

Technical field

The invention relates to the technical field of ceramic tubes for high-intensity gas discharge, and specifically relates to a method for preparing irregularly symmetrical precision special-shaped ceramic tubes for LED electric vacuum packaging.

Background technique

The ceramic tubes of existing ceramic metal halide lamps usually adopt a "five-piece set" structure of an axis-rotating middle tube, an end tube, and a tail tube, or an improved "two-piece set" structure of an axis-rotating structure, so they can be molded by hot pressing. , made by a co-firing process with plugs; however, for special-purpose ceramic tubes for LED electric vacuum packaging, which need to meet the requirements of rarefied gas dynamics and thermodynamics, a special irregular symmetrical precision special-shaped ceramic tube structure is used. Due to its The ends at both ends have an irregular symmetrical structure, and the hollow cavity inside the end has an inverted structure. The existing hot-pressure injection molding process for producing ceramic metal halide lamp ceramic tubes cannot remove the core of the hollow cavity, resulting in The existing ceramic tube production process for ceramic metal halide lamps cannot complete the manufacturing of irregularly symmetrical precision special-shaped ceramic tubes for LED electric vacuum packaging.

Contents of the invention

In order to overcome the deficiencies in the background technology, the present invention discloses a method for preparing an irregularly symmetrical precision special-shaped ceramic tube for LED electric vacuum packaging. The irregularly symmetrical precision special-shaped ceramic tube for LED electric vacuum packaging includes a middle round tube, irregular symmetrical ends The head and tail pipes; the middle round pipe and the tail pipe are made into the middle round pipe blank and the tail pipe blank through the screw extrusion process; the irregular symmetrical ends are made into the irregular symmetrical ends by hot pressing injection molding of the elastic inflatable core Blank; the middle round tube blank, the tail tube blank, and the irregular symmetrical end blank are assembled into an irregularly symmetrical precision special-shaped ceramic tube blank for LED electric vacuum packaging. Finally, it is pre-fired and sintered at high temperature to form an irregularly symmetrical ceramic tube blank for LED electric vacuum packaging. Precision special-shaped ceramic tube.

In order to achieve the purpose of the invention, the present invention adopts the following technical solution: a method for preparing an irregularly symmetrical precision special-shaped ceramic tube for LED electric vacuum packaging. Refer to Figures 1 and 2 of the description: The irregularly symmetrical precision ceramic tube for LED electric vacuum packaging The special-shaped ceramic pipe includes a middle circular pipe, irregular symmetrical ends, and tail pipes. The irregular symmetrical ends are fixedly installed on both ends of the middle circular pipe, and the tail pipes are fixedly installed on the outer end faces of the irregular symmetrical ends; among them, the irregular symmetrical ends There is a hollow cavity inside the head, and the local size inside the hollow cavity is larger than the opening size of the irregular symmetrical end, so the hollow cavity inside the irregular symmetrical end actually has an undercut structure; in the middle round pipe and tail pipe of the present invention The middle round tube blank and the tail tube blank are made through the screw extrusion process; the irregular symmetrical end heads are made into the irregular symmetrical end blanks through hot pressing injection molding of the elastic inflatable core to solve the problem that cannot be solved by the existing hot pressing injection molding process. The demoulding problem of the irregular symmetrical end core; the middle round tube blank, the tail tube blank, and the irregular symmetrical end blank are assembled into irregular symmetrical precision special-shaped ceramic tube blanks for LED electric vacuum packaging, irregular symmetrical precision special-shaped ceramics The tube blank is pre-fired and sintered to make an irregular symmetrical precision special-shaped ceramic tube for LED electric vacuum packaging.

Further, the hot-pressure injection molding of the elastic inflatable core adopts the hot-pressure injection molding of the elastic inflatable core. The hot-pressure injection molding of the elastic inflatable core is provided with an elastic inflatable core of non-uniform wall thickness. See Figures 5 and 6 of the description. : The non-uniform wall thickness elastic inflatable core is provided with a thinned non-uniform wall thickness at the arc transition where the internal surfaces intersect. When the elastic inflatable core is hot-pressed and injection molded, the non-uniform wall thickness elastic inflatable core Inflated with high-pressure gas, the elastic inflatable core with non-uniform wall thickness mainly expands and deforms along the thinned non-uniform wall thickness, forming a hollow cavity inside the irregular symmetrical end; after the hot-press injection molding of the irregular symmetrical end is completed, After the non-uniform wall thickness elastic inflatable core discharges the high-pressure gas, it shrinks along the thinned non-uniform wall thickness and returns to the original uninflated state. At this time, the maximum size of the non-uniform wall thickness elastic inflatable core is smaller than the irregular symmetrical end. The opening size allows the non-uniform wall thickness elastic inflatable core to be smoothly demoulded from the hollow cavity inside the irregular symmetrical end.

Furthermore, before the middle round tube blank, tail tube blank, and irregular symmetrical end blank are assembled, their assembly surfaces must be precision turned to ensure the assembly clearance of the middle round tube blank, tail tube blank, and irregular symmetrical end blank. , thereby improving the connection quality after high-temperature sintering between the assembly surfaces of the middle round tube blank, the tail tube blank, and the irregular symmetrical end blank.

Furthermore, before the irregular symmetrical end blanks and tail pipe blanks are assembled, their assembly surfaces need to be coated with ceramic slurry; although before the intermediate round tube blanks, tail pipe blanks, and irregular symmetrical end blanks are assembled, their assembly surfaces have been After precision turning, there is still an assembly gap between the assembly surfaces. The existence of the assembly gap will cause local bubble problems between the assembly surfaces after high-temperature sintering, thereby reducing the connection between the assembly surfaces after high-temperature sintering. Quality; after coating ceramic slurry on the assembly surfaces of irregular symmetrical end pre-sintered materials and tail pipe pre-sintered materials, the ceramic slurry can fill between the assembly surfaces, thereby improving the local bubbles between the assembly surfaces after high-temperature sintering. problem; additional explanation is that the coating method of ceramic slurry on the assembly surface is to immerse the assembly surface in ceramic slurry, so that the ceramic slurry is naturally coated on the assembly surface. If this method is used to coat the intermediate round tube blank When the assembly surface is coated with ceramic slurry, the ceramic slurry will be coated on the inner circular surfaces at both ends of the intermediate circular tube blank, thus affecting the diameter of the inner circular surfaces at both ends of the intermediate circular tube after high-temperature sintering, so the intermediate circular tube blank Before assembly, the ceramic slurry is not coated; the composition of the ceramic slurry is the same as the slurry for hot injection molding or screw extrusion molding; when applying the ceramic slurry, the temperature of the ceramic slurry is maintained Between 60℃-80℃.

Further, the pre-sintering conditions for the irregular symmetrical precision special-shaped ceramic tube blanks are: heating rate 5°C/min, temperature 1300°C-1500°C, and heat preservation for 3-10 minutes; the sintering conditions for the irregular symmetrical precision special-shaped ceramic tube blanks are: Temperature 1700℃-1800℃, holding time 2-3 hours.

Further, during the pre-sintering and sintering processes, the vacuum furnace is filled with nitrogen.

Due to the adoption of the technical solution as described above, the present invention has the following beneficial effects: The present invention discloses a method for preparing an irregularly symmetrical precision special-shaped ceramic tube for LED electric vacuum packaging. The pipe includes a middle round pipe, irregular symmetrical ends, and tail pipes; the middle round pipe and tail pipes are made into intermediate round pipe blanks and tail pipe blanks through a screw extrusion process; the irregular symmetrical ends are heated through an elastic inflatable core Irregular symmetrical end blanks are made by injection molding; the intermediate round tube blank, tail pipe blank, and irregular symmetrical end blanks are assembled into irregular symmetrical precision special-shaped ceramic tube blanks for LED electric vacuum packaging, which are pre-fired and sintered at high temperature. The use of irregularly symmetrical precision special-shaped ceramic tubes for LED electric vacuum packaging solves the technical problem of manufacturing irregularly symmetrical precision special-shaped ceramic tubes for LED electric vacuum packaging.

Description of the drawings

Figure 1 is a schematic diagram of the appearance of an irregularly symmetrical precision special-shaped ceramic tube for LED electric vacuum packaging;

Figure 2 is an exploded schematic diagram of the structure of an irregularly symmetrical precision special-shaped ceramic tube for LED electric vacuum packaging;

Figure 3 is a schematic diagram of the appearance of the non-uniform wall thickness elastic inflatable core in the uninflated state;

Figure 4 is a schematic diagram of the appearance of the elastic inflatable core with non-uniform wall thickness in the inflated state.

Figure 5 is a schematic cross-sectional view of an elastic inflatable core with non-uniform wall thickness;

Figure 6 is a schematic cross-sectional view of an elastic inflatable core with non-uniform wall thickness.

In the picture: 1. Middle round pipe; 1.1. Middle round pipe blank; 2. Irregular symmetrical end; 2.1. Irregular symmetrical end blank; 3. Tail pipe; 3.1. Tail pipe blank; 4. Non-uniform wall thickness Elastic inflatable core; 4.1, non-uniform wall thickness.

Detailed ways

The present invention can be explained in detail through the following examples, and the purpose of disclosing the present invention is to protect all technical improvements within the scope of the present invention.

A method for preparing an irregularly symmetrical precision special-shaped ceramic tube for LED electric vacuum packaging. See Figure 1 of the description: the irregularly symmetrical precision special-shaped ceramic tube for LED electric vacuum packaging includes a middle round tube 1, an irregular symmetrical end 2, The tail pipe 3 has a hollow cavity inside the irregular symmetrical end 2; the middle circular pipe 1, the irregular symmetrical end 2 and the tail pipe 3 use the same ceramic slurry, and the ceramic slurry consists of silicon nitride powder, Yttrium oxide micropowder, 10% polyvinyl alcohol aqueous solution, glycerin, and paraffin wax; see Figure 2 of the instruction manual: the ceramic slurry is produced through a screw extrusion process to produce the intermediate round tube blank 1.1 and the tail tube blank 3.1, which are heated through the elastic inflatable core The irregular symmetrical end blank 2.1 was produced by the injection mold. The molding temperature of the elastic inflatable core hot injection mold was 70°C and the molding pressure was 0.8 Pa. An elastic rubber material was installed in the elastic inflatable core hot injection mold. The elastic inflatable core 4 with uniform wall thickness and the elastic inflatable core 4 with non-uniform wall thickness is in a contracted state when it is not filled with high-pressure air. The state of the elastic inflatable core 4 with non-uniform wall thickness after being filled with high-pressure gas and expanded is shown in Figure 4 of the description;

The wall thickness distribution of the elastic inflatable core 4 with non-uniform wall thickness can be found in Figures 5 and 6 of the description: It should be supplemented that the elastic inflatable core 4 with non-uniform wall thickness is provided with a thickness at the arc transition where its internal surfaces intersect. The thinned non-uniform wall thickness 4.1, the width and thickness of the non-uniform wall thickness 4.1 are obtained through computer simulation. The preliminary structural parameters obtained through computer simulation are used to produce the non-uniform wall thickness elastic inflatable core 4 experimental sample. Through the non-uniform The wall thickness elastic inflatable core 4 experimental sample is used to make the irregular symmetrical end blank 2.1 sample, and the irregular symmetrical end blank 2.1 sample is measured and compared with the expected irregular symmetrical end blank 2.1 design size, and based on the comparison results Correct and compensate the structural dimensions of the experimental sample of the non-uniform wall thickness elastic inflatable core 4 until the non-uniform wall thickness elastic inflatable core 4 is obtained for production;

When the elastic inflatable core is hot-pressed and injection molded, the non-uniform wall thickness elastic inflatable core 4 is filled with 25MPa high-pressure nitrogen. The non-uniform wall thickness elastic inflatable core 4 mainly expands and deforms along the thinned non-uniform wall thickness 4.1, forming uneven The hollow cavity inside the regular symmetrical end; after the hot-press injection molding of the irregular symmetrical end is completed, the non-uniform wall thickness elastic inflatable core 4 discharges high-pressure gas, and then shrinks along the thinned non-uniform wall thickness 4.1, returning to the original state. In the original state of inflation, at this time, the maximum size of the non-uniform wall thickness elastic inflatable core 4 is smaller than the opening size of the irregular symmetrical end 2, so that the non-uniform wall thickness elastic inflatable core 4 is from the inside of the irregular symmetrical end 2. Smooth demoulding in the hollow cavity;

The prepared intermediate round tube blank 1.1, irregular symmetrical end blank 2.1, and tail tube blank 3.1 were ventilated and dried at 50°C for 24 hours, and then the dried intermediate round tube blank 1.1, tail tube blank 3.1, and irregular The assembly surface of the symmetrical end blank 2.1 is precision turned;

Dip the assembly surface of the precision-machined irregular symmetrical end blank 2.1 into 80°C ceramic slurry, and then quickly assemble it on both ends of the middle round tube blank 1.1; immerse the assembly surface of the precision-machined tail pipe blank 3.1 into 80°C ceramic slurry. °C ceramic slurry, and then quickly assembled on the outer end of the irregular symmetrical end blank 2.1 to assemble into an irregular symmetrical precision special-shaped ceramic tube blank for LED electric vacuum packaging; an irregular symmetrical precision special-shaped ceramic tube for LED electric vacuum packaging The blank is ventilated and dried in a 50℃ environment for 24 hours;

The dried irregular symmetrical precision special-shaped ceramic tube blanks for LED electric vacuum packaging are pre-fired in a vacuum furnace: During pre-firing, the vacuum furnace is filled with atmospheric nitrogen and heated to 1500℃ at a heating rate of 5℃/min. Keep the temperature for 10 minutes; high-temperature sintering is carried out in a vacuum furnace. The vacuum furnace is filled with normal pressure nitrogen and raised to 1800°C at a speed of 10°C/min. The heat preservation and sintering is performed for 2 hours. Finally, the irregular symmetrical precision special shape for LED electric vacuum packaging is obtained. Finished ceramic tube.

The irregularly symmetrical precision special-shaped ceramic tube for LED electric vacuum packaging produced by the inventive process has good dimensional accuracy and comprehensive mechanical strength. It can ensure that no cracking, erosion and ablation will occur when working at a temperature of 1200°C for a long time.

The parts not described in detail in the present invention are prior art.

Claims (6)

1. The preparation method of the irregular symmetrical precise special-shaped ceramic tube for the LED electric vacuum packaging comprises a middle circular tube (1), an irregular symmetrical end head (2) and a tail tube (3), wherein a hollow cavity is arranged in the irregular symmetrical end head (2); the irregular symmetrical end heads (2) are fixedly arranged at two ends of the middle circular tube (1), and the tail tube (3) is fixedly arranged at the outer end face of the irregular symmetrical end heads (2); the method is characterized in that: the middle round tube (1) and the tail tube (3) are manufactured into a middle round tube blank (1.1) and a tail tube blank (3.1) through a screw extrusion process; the irregular symmetrical end head (2) is manufactured into an irregular symmetrical end head blank (2.1) through hot-press injection molding of an elastic inflatable core; the middle round tube blank (1.1), the tail tube blank (3.1) and the irregular symmetrical end blank (2.1) are assembled into an irregular symmetrical precise special-shaped ceramic tube blank for LED electric vacuum packaging; the irregular symmetrical precise special-shaped ceramic tube blank is presintered and sintered to prepare the irregular symmetrical precise special-shaped ceramic tube for the LED electric vacuum packaging.

2. The method for preparing the irregular symmetrical precise special-shaped ceramic tube for the LED electric vacuum packaging, which is disclosed in claim 1, is characterized in that: the elastic inflation core hot-press injection molding adopts an elastic inflation core hot-press injection molding die, and an elastic inflation core (4) with non-uniform wall thickness is arranged in the elastic inflation core hot-press injection molding die; when the elastic inflatable core is subjected to hot-press injection molding, the elastic inflatable core (4) with non-uniform wall thickness is inflated with high-pressure gas and then deformed and expanded to form a hollow cavity in the irregular symmetrical end head (2); after the hot-press injection molding of the irregular symmetrical end head (2) is finished, the non-uniform wall thickness elastic inflatable core (4) discharges high-pressure gas to shrink, and then the air is separated from the hollow cavity in the irregular symmetrical end head (2).

3. The method for preparing the irregular symmetrical precise special-shaped ceramic tube for the LED electric vacuum packaging, which is disclosed in claim 2, is characterized in that: before the middle round pipe blank (1.1), the tail pipe blank (3.1) and the irregular symmetrical end head blank (2.1) are assembled, the assembly surfaces of the middle round pipe blank and the tail pipe blank are subjected to precise turning.

4. The method for preparing the irregular symmetrical precise special-shaped ceramic tube for the LED electric vacuum packaging, which is disclosed in claim 2, is characterized in that: before the middle round tube blank (1.1) and the tail tube blank (3.1) are assembled, the assembly surfaces of the middle round tube blank and the tail tube blank are coated with ceramic slurry.

5. The method for preparing the irregular symmetrical precise special-shaped ceramic tube for the LED electric vacuum packaging, which is disclosed in claim 2, is characterized in that: the irregular symmetrical precise special-shaped ceramic tube blank is subjected to presintering conditions: heating at a speed of 5 ℃/min, and keeping the temperature at 1300-1500 ℃ for 3-10 minutes; the sintering conditions of the irregular symmetrical precise special-shaped ceramic tube blank are as follows: the temperature is 1700-1800 ℃; the heat preservation time is 2-3 hours.

6. The method for preparing the irregular symmetrical precise special-shaped ceramic tube for the LED electric vacuum packaging, which is disclosed in claim 2, is characterized in that: in the presintering and sintering process, nitrogen is filled in the vacuum furnace.