Preparation method of shell mold for investment casting of TiAl based alloy

Abstract

The invention relates to a preparation method of a shell mold for investment casting of a TiAl based alloy, and belongs to the technical field of precision casting. The preparation method comprises the following steps that: firstly, ZrO2 and zirconia sol are prepared into a slurry; after the slurry is coated with a wax pattern, ZrO2 sand with a particle degree of 120 to 180 meshes is spread; Al2O3 and ethyl silicate hydrolyzate are prepared into a slurry, and then after the slurry is coated with a mold shell, Al2O3 sand with a particle degree of 60 to 90 meshes is spread, the slurry coating and the sand spreading are repeated for several times, the sand is Al2O3 sand with the particle degree of 40 to 50, 20 to 30, and 6 to 10 meshes sequentially, and drying is carried out; and dewaxing and roasting are carried out. The preparation method has the advantages that: the strength of the mold shell is sufficient, the production cycle is short, the quality of the inner surface of the mold shell is good, the reaction between TiAl based alloy castings and the mold shell is small after casting, and the castings have high surface quality.

Description

technical field [0001] The invention belongs to the technical field of precision casting, and in particular relates to a preparation method of a TiAl-based alloy shell mold for investment casting. Background technique [0002] TiAl-based alloy has the advantages of high strength, low density, high elastic modulus, good oxidation resistance and creep performance, and is a kind of light-weight high-temperature structural material with great potential. It is a rapid development in the field of titanium casting in recent years. A class of alloys [E.A.Loria.Quo vadis gamma titanium aluminumide.Intermetallics.2001.9:997-1001]. TiAl-based alloys are expected to be used in jet engines and turbines and other aerospace and high-temperature-resistant parts of the automotive industry, as well as wings and shells of ultra-high-speed aircraft, and are considered to be a new generation of lightweight high-temperature-resistant structural materials with the most application potential [Li Ji...

AI Technical Summary

Problems solved by technology

[0003] Because TiAl-based alloys have poor room temperature plasticity and obvious room temperature brittleness, their elongation during stretching is less than 1%, and the grains will grow sharply during hot working, resulting in further embrittlement, so the machinability is very poor. making it difficult to apply

[0004] In view of the characteristics of TiAl-based alloys, forging is obviously laborious and wasteful, especially when making parts with complex shapes.