Titanium alloy structural part and laser melting deposition forming method thereof

Abstract

The invention belongs to the technical field of additive manufacturing and relates to a titanium alloy structural part and a laser melting deposition forming method thereof. The method includes steps:determining prone-to-crack areas of the titanium alloy structural part according to the size and structure of the titanium alloy structural part; adopting the laser melting deposition forming methodfor acquiring the titanium alloy structural part, wherein the grain morphology is controlled to be isometric crystal in forming of the prone-to-crack areas, and the grain morphology is controlled to be columnar crystal in forming of other areas. Deposited plasticity and ductility of the prone-to-crack areas are improved, serious cracking risks in a forming process of the titanium alloy structuralpart are effectively avoided and eliminated, and high forming efficiency is guaranteed. Compared with the prior art, the titanium alloy structural part and the laser melting deposition forming methodthereof have advantages that an interconnection process is avoided, special fixtures for clamping, positioning and the like are avoided, repeated machining before interconnection of small-size structures is avoided, once integral quick manufacturing of the titanium alloy structural part can be realized, and a forming period is remarkably shortened.

Description

technical field [0001] The invention relates to a titanium alloy structural part and a laser melting deposition forming method thereof, belonging to the technical field of additive manufacturing. Background technique [0002] At present, the processing technology of large-scale titanium alloy main load-bearing structural parts of my country's Long March series of launch vehicles adopts forging / machining methods, and it is generally faced with various manufacturing processes such as vacuum melting and casting of large-scale titanium alloy ingots, preparation of large-scale forging billets, and processing of large-scale forging molds. The complex process, large machining allowance, extremely low material utilization rate (generally less than 5-10%), long CNC machining cycle and other outstanding problems have gradually made it difficult to meet the high performance and high Reliability manufacturing needs. Laser melting deposition technology, using alloy powder as raw material,...

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Problems solved by technology

[0003] However, due to the point-by-point, line-by-surface processing characteristics, large-scale structural parts (the envelope size of at least one side in the laser melting deposition forming plane is greater than 1000mm) are extremely serious in the thermal stress accumulation during the laser melting deposition manufacturing process, which can easily lead to serious damage to the product. deformation crack failure

[0004] At present, the main solution to this type of problem is to first discretize the scale of the large structure, disassemble it into multiple small-scale structures, and then process and manufacture them one by one, and finally realize the interconnection of multiple small-scale structures through the laser melting deposition process. , this kind of scheme can effectively solve the above problems, but it still faces the difficulty of controlling the consistency of the organization and performance of the two connected small-sized structural substrates and the interconnection area, special tooling such as clamping and positioning are required during the interconnection process, and various parts before interconnection After the small-sized structure is formed by laser melting deposition, it must be interspersed with many times of machining, the process is complicated and cumbersome, and the production and turnover cycle are significantly increased.

In addition, the overall structure of many large titanium alloys has almost no obvious transition structure, and cannot be divided into multiple small-scale structures

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