Method for improving deformability of oxide ceramic shells precisely cast by titanium-aluminum alloy

An oxide ceramic and precision casting technology, applied in the field of titanium aluminum alloy precision casting, can solve problems such as titanium aluminum alloy cracks, and achieve the effects of increasing toughness, reducing the tendency of casting defects, and improving collapsibility.

Active Publication Date: 2016-02-03
SHANGHAI SPACE PRECISION MACHINERY RES INST
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] Aiming at the defects in the prior art, the purpose of the present invention is to provide a method for improving the retreat of titanium-aluminum alloy investment casting oxide ceramic shell, so as to solve the problem of cracks in the titanium-aluminum alloy casting process

Method used

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  • Method for improving deformability of oxide ceramic shells precisely cast by titanium-aluminum alloy
  • Method for improving deformability of oxide ceramic shells precisely cast by titanium-aluminum alloy
  • Method for improving deformability of oxide ceramic shells precisely cast by titanium-aluminum alloy

Examples

Experimental program
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Effect test

example 1

[0032] Winding polypropylene filament during the preparation of example 1 type shell

[0033] After the surface shell is dried, polypropylene filaments with a width of 0.3-1 mm and a thickness of 0.2-0.8 mm are evenly wound on the surface of the shell during the process of coating and hanging the back shell. The distance between wires during winding should be determined by the actual shape of the shell, but the gap should be greater than 3mm and less than 12mm, single-layer winding. After the winding is completed, paste, hang sand and dry.

[0034] The titanium-aluminum alloy precision casting back layer is coated with a total of 6 to 8 layers, and the polypropylene is continued to be wound according to the above method during the preparation of the remaining back layer, and the total number of winding layers is not more than 5 layers.

example 2

[0035] Example 2 prepares the back layer slurry containing graphite powder

[0036] The main components of the back layer slurry are coal gangue powder and silica sol, and the powder-to-liquid ratio is 3:1. The graphite powder accounts for 1% to 4% of the total weight of the paint, and the particle size of the graphite powder is 60 to 100 mesh. Accounting for 0.01% to 0.03% of defoaming agent n-butanol and 0.02% to 0.05% of wetting agent fatty alcohol polyoxyethylene ether.

[0037] Preparation process: first add the corresponding silica sol glue, after stirring, add the wetting agent fatty alcohol polyoxyethylene ether, then add the corresponding amount of coal gangue powder and graphite powder, stir evenly, then add the defoamer n-butanol.

[0038] After the back layer paint is evenly stirred with a mixing bucket for 24 hours, its viscosity should be about 10S to 30S. If the viscosity is too high, add an appropriate amount of silica sol, and if the viscosity is too low, a...

example 3

[0039] Example 3 type shell roasting and testing

[0040] After the mold shell is prepared, dewaxing and roasting are carried out. The roasting temperature is 900°C-1050°C and the time is 2h-5h. Concession, image 3 The cross-sectional morphology of the shell prepared by the traditional process, Figure 4 The cross-sectional morphology of the shell prepared for the present invention.

[0041] By carrying out the mold shell flexural strength test on the Instron-550 type universal material testing machine, the strength of the mold shell prepared by the test result surface after roasting will be 16% lower than the mold shell prepared by the traditional silica sol process, and the traditional mold shell is dry. The strength is 0.06MPa, while the dry strength of the shell prepared by the present invention is only 0.05MPa. This is because after high-temperature roasting, polypropylene and graphite powder form pores after burning, which reduces the strength and improves the coll...

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Abstract

The invention discloses a method for improving the deformability of oxide ceramic shells precisely cast by titanium-aluminum alloy. The method comprises the steps that polypropylene fiber and graphite powder are added in the preparing process of precisely casting the shells, and combustion is achieved through high-temperature roasting of the polypropylene fiber and the graphite powder so as to form pores in the shells and improve the deformability. Particularly, in the steps of slurry preparation and slurry coating on the shells in the preparation process of precisely casting the shells, the polypropylene fiber is wound on the surfaces of the oxide shells, and back-layer slurry containing graphite powder is adopted for coating. By the adoption of polypropylene fiber winding during shell preparation and preparation of the back-layer slurry containing the graphite powder in the method, the deformability of the shells is effectively improved, accordingly the cold and hot cracking tendency occurred in the solidification process of castings is effectively reduced, and the qualified rate of the castings is improved.

Description

technical field [0001] The invention relates to the field of titanium-aluminum alloy precision casting, in particular to a method for improving the retreatability of an oxide ceramic shell in titanium-aluminum alloy precision casting. Background technique [0002] Titanium-aluminum alloy (also known as titanium-aluminum-based intermetallic compound) is a new type of lightweight high-temperature structural material with a density less than 50% of that of nickel-based alloys, and has both metal and ceramic properties. They not only have the advantages of light weight, high specific strength, high specific rigidity, corrosion resistance, wear resistance, high temperature resistance and excellent oxidation resistance, but also have excellent mechanical properties at room temperature and high temperature, and their service temperature can reach 700-1000 °C . This makes it highly valued by researchers, and it has become a very competitive material for heat-resistant structural pa...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B22C3/00
Inventor 王宝兵李宝辉余国康何凯陈舸
Owner SHANGHAI SPACE PRECISION MACHINERY RES INST
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