A titanium alloy structural part and laser melting deposition forming method thereof

Abstract

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. The method includes the following steps: according to the size and structure of the titanium alloy structural part, determine the crack-prone area of ​​the titanium alloy component; adopt the laser melting deposition forming method to obtain the titanium alloy structural part, wherein, when forming the crack-prone area Control the grain shape as equiaxed grain, and control the grain shape as columnar grain when forming other regions. The invention improves the plasticity and elongation rate of the deposited state in the easily cracked area, effectively avoids and eliminates the risk of serious cracking in the forming process of titanium alloy structural parts, and at the same time ensures high forming efficiency; compared with the prior art, the invention has no interconnection The process does not require special tooling such as clamping and positioning, and does not involve multiple machining processes before the interconnection of small-sized structures. It can realize the one-time overall rapid manufacturing of titanium alloy structural parts, and significantly shorten the forming cycle.

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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