Method for preparing TiAl alloy structural member by selective laser melting

Abstract

The invention provides a method for preparing a TiAl alloy structural member by selective laser melting, which comprises the steps of 1) drying and heating gas atomization TiAl powder; 2) clamping a base plate on a working platform after being processed, and preheating the base plate; 3) drying and heating an inert protective gas, and then filling the inert protective gas into a working room, wherein the oxygen content of the working room is reduced to 0.01% or below; 4) preparing according to a mode of scanning the TiAl powder by means of low power laser pre-sintering, high-power laser melting and low power laser heat preservation layer by layer by using a selective laser melting technology until a forming member is completely processed; and 5) slowing cooling the forming member to the room temperature in a vacuum environment. The TiAl alloy structural member is prepared according to the procedures of low power laser scanning pre-sintering, high power laser scanning melting and low power laser scanning heat preservation and slow cooling, so that the temperature gradient and internal stress in the forming process of the structural member are greatly reduced, the generation of cracks is effectively inhibited, and a TiAl alloy sample with high density and good comprehensive performance is obtained.

Description

technical field [0001] The invention belongs to the field of manufacturing alloy structural parts, and in particular relates to a method for preparing TiAl alloy structural parts by laser selective melting. Background technique [0002] TiAl superalloy has the advantages of excellent high elastic modulus, corrosion resistance, wear resistance, high temperature resistance, excellent oxidation resistance and flame retardancy. At present, it has become a very competitive material for heat-resistant structural parts of aerospace, aviation and automotive engines. At present, traditional methods such as investment casting and thermoplastic processing are mainly used to prepare TiAl parts. [0003] However, due to its brittleness at room temperature and poor deformability at high temperature, its processing and forming are greatly limited. The room temperature brittleness makes the TiAl alloy easy to crack, which makes it difficult to deform and process. In order to prevent crac...

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Problems solved by technology

[0006] In order to overcome the problem of difficult preparation of TiAl alloy complex structural parts in the prior art, the object of the present invention is to provide a method for preparing TiAl alloy structural parts by laser selective melting. The manufacturing method first heats the powder, protective gas and substrate, and then Through the step-by-step heating and cooling process of "low-power laser scanning pre-sintering-high-power laser scanning melting-low-power laser scanning heat preservation and slow cooling", the temperature gradient and internal stress during the forming process are greatly reduced, and the temperature is effectively suppressed. cracks, obtained a TiAl alloy sample with high density and good comprehensive performance

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