SU1252036A1 - Apparatus for investment casting by oriented crystallization - Google Patents

Description

The invention relates to foundry production, in particular, to devices for the manufacture of products with directional solidification from hard magnetic materials.

The purpose of the invention is to simplify the process and save materials.

Figure 1 shows a diagram of a part of the device; au figure 2 - node I in FIG. 1.

The device consists of a pallet-cooler 1, containing on the upper heat-removing surface a layer of powder 2 of material with high thermal conductivity and linear particle sizes equal to 0.7-1.0 maximum linear sizes of particles of the grinding material of the mold 3, t grams of heat insulating material cover 4.

The device works as follows.

 The hopper 1 is filled with a powdered material with a high thermal conductivity and a layer 6 thickness equal to 1.0-1.5 wall thickness of the mold. Then, a preheated 1300 ° C is heated onto the powder layer.

80 5727

200-300

Cast iron

Cast Iron Graphite

Aluminum

79-81

75-76 79-81

74-77

As can be seen from the table, the optimal one is called the complexity of creating a uniform value of the thickness of a layer of powder of a composite layer and when sinking to a powder, it is 1.0–1.5 times the thickness of the bottom of the foundry55 with its own weight and weight

molds. alloy casting mold does not ensure the low quality of the structure casts the necessary thermal contact

when the thickness of the layer of powder is 1, 0 mm you are “bottom with a cooling tray.

five

0

five

casting mold. After cooling the bottom of the molds installed on the refrigerator, the melt of the hard magnetic alloy is washed down into the mold to 00-900 ° C and the cover-hood is installed on the cooling tray.

Upon completion of the crystallization of the melt, the Shielding 4 case and the mold from the refrigerator tray 1 are removed in the mold and the powder is extracted. The process then repeats. .

Example. The melt temperature of the hard magnetic alloy (UN14DK25BA) before pouring is 1750-1800 C, the temperature of the mold before pouring the melt is 1300 ° C, the temperature of the cold core before installing the mold is 20 s, the particle size of the sand used to make the mold bottom shape 2 mm.

The optimal sizes of the particles and the thickness of the powder layer are given in the table according to averaged data. The criterion for choosing the optimal particle size and layer thickness is the maximum height of the zone of columnar crystals in the casting.

100

70-74 88-90

84-87

87-89

69-71 79-83

80-82

312

When the layer thickness is A mm or more, the casting structure deteriorates due to an increase in the distance between the bottom of the mold and the cooling tray above the permissible, i.e. reducing the thermal conductivity of the powder layer.

The optimum sizes of the particles of the powder are in the range of 0.7-1.0, 0 of the particle size of the strip mold material.

The use of powders of tin and lead showed the following. During crystallization of the melt in the form, they are partially melted in the region adjacent to the bottom of the form, and

also its partial sintering. Hour

The melted and sintered powder, together with the mold, is removed from the refrigerator tray, which leads to additional material loss and complication of the technological process due to the need to restore the powder layer in the device. In addition, the metal that remains on the shell of the mold does not allow its reuse in the technological process.

The use of metal powder with a high heat conductor, Gyu (aluminum grit, cast iron fraction) in the device will make it possible to eliminate losses of g alli.

Editor N. Bobkova

Compiled by Y. Yakovlev

Tehred L. Serdyukova Corrector V. Sinitska

Order 4565/12 Circulation 757 Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab .; d. A / 5

Production and printing company, Uzhgorod, st. Design, D

FIG. 2

Claims (1)

DAY CASTING DEVICE FOR SIGNED DIGESTAL CRYSTALIZATION MODELS, containing a casting mold made of refractory material, a refrigerator tray, a layer of low-melting alloy located on a refrigerator tray under the casting mold and a heat-insulating casing-cover, characterized in that, with the aim of simplifying the process and simplifying the process to simplify the process material saving, fusible alloy is located in the form of a powder layer with linear particle sizes equal to 0.7-1.0 maximum particle sizes of the refractory mold material, and the layer thickness is 1.0- 1.5 mold wall thickness. a FIG. /