钛铝合金表面熔覆涂层的制备及组织特征

Preparation and structure characteristics of the TiAl alloy surface clad coating

针对现有熔覆基体与熔覆层结合不紧密、工艺参数难以控制的缺陷,采用高功率连续CO2横流激光器及配套数控加工系统,实现了将Ni60B合金粉末均匀密实地熔覆在钛铝合金表面的方案。结合扫描电镜、金相分析、硬度测试等手段研究了输出功率、扫描速度对熔覆层组织和性能的影响。研究发现,基体材料与熔覆层之间存在明显的合金元素扩散现象,熔覆层与基体结合紧密;当激光功率为4.0 Kw,扫描速度为100 mm·min-1时,熔覆层的硬度达最高达HV 900以上。

In light of the defects containing the loose combination of existing cladding substrate and the claddin~ layer, and the difficulty to control the process parameters. This essay selected high power CW CO2 cross flow-lasel and supporting NC matching system, achieved the programmer that make Ni60B alloy powder uniformly compact cladding on the surface of the TiAI alloy. Combined with the SEM, metallographic analysis and hardness test were used to study the microstructure and properties effect by output power and scanning speed of layer cladding. The study found that, there exists obvious phenomenon of alloy element diffusion between base material and the cladding layer, close combination of cladding layer and the substrate.When the power is 4.0Kw and the scanning speed is 100 mm·min^-1, the hardness of the clad layers can reach up to HV 900.