The melting, solidification and cooling processes of tantalum tungsten alloy laser forming are carried out under extremely fast conditions, and improper parameter control is easy to have defects such as poor intercambium bonding, pores, cracks and so on. The forming quality of tantalum tungsten alloy is comprehensively affected by laser power, scanning speed, scanning path, layer thickness, spot diameter and other parameters. Parameter setting is the key to obtain tantalum tungsten alloy components by laser selective melting forming.
By using different solid forming parameters to form metallographic samples and surface quality test pieces, the invention studies the sintering condition of the surface of the sample during forming, the distribution and quantity of defects such as non-fusion inside the sample after forming, pores, cracks, etc., and studies the influence of laser power, scanning rate, track spacing, scanning path and other parameters on the internal defects and surface quality of the entity. At the same time, due to the high melting point of tantalum tungsten alloy (above 3000℃) and the large residual internal stress in the alloy after rapid solidification, it is easy to cause cracking and deformation of thin-walled parts, and it is easier for thin-walled shell components to shrink and deform, so it is difficult to control the forming accuracy between thin walls. The applicant uses 3D scanner to measure the size of typical feature parts, and according to the size data of typical tantalum tungsten components formed, the dimensional accuracy is corrected through local structure optimization, model size compensation and scanning spot migration technology.
Therefore, by reasonably designing laser forming parameters, the invention can not only form tantalum tungsten alloy components without poor interlayer bonding, pores, cracks and other defects, but also produce TaW alloy based on additive with higher material efficiency ratio, lower processing cost and higher efficiency than TaW alloy using traditional powder metallurgy. The problems of low utilization rate, high cost, long processing cycle and low yield of tantalum tungsten alloy are solved.
According to different support structure designs and wire-cutting methods, the invention can print out different shape structure prototypes, including hollow structure, block, outer ring, plate and cavity.
Further, also includes a post-treatment process, the post-treatment process includes heat treatment of tantalum tungsten alloy members, the parameters of the heat treatment are: heat treatment at 1500℃ for 2h, and then furnace cooling.
