GH4133镍基高温合金激光冲击强化研究

为了研究激光冲击强化技术在高温部件上应用的可行性,研究了GH4133镍基高温合金激光冲击后强化效果的热稳定性。分别采用激光冲击强化、激光冲击强化加保温的方法进行处理,并利用SEM、显微硬度和残余应力的测试方法分析了温度对激光冲击处理后GH4133材料微观组织和力学性能的影响。通过冲击强化后涡轮叶片的高温疲劳试验验证强化效果的热稳定性,并分析其高温下的强化机制。结果表明,激光冲击强化可以在GH4133镍基高温合金表层产生较大残余压应力,细化晶粒;并且在温度作用下,激光冲击GH4133合金形成的细化晶粒在析出相的钉扎作用下具有较好的热稳定性。另一方面残余压应力的应力集中减小,分布均匀。两者的共同作用提高了强化效果的热稳定性,有利于疲劳性能的提高。

Laser Shock Peening of GH4133 Nickel-based Superalloy

In order to investigate the feasibility of laser shock peening (LSP) on the components suffering high temperature in work, the thermal stability of LSP effects on GH4133 nickel-based superalloy were studied. GH4133 nickel-based superalloy samples were treated by laser shock peening and laser shock peening+annealing separately. The thermal stability was examined by scanning electron microscopy (SEM), microhardness and residual stress tests. High-temperature fatigue of turbine blades was tested and the mechanism of fatigue life improvement was also discussed. Results show that high-amplitude residual compressive stress and grain refinement are generated, and precipitated phase of GH4133 alloy treated by LSP has a great impact on thermal stability for the refined grains. On the other hand, stress concentration slows up and distributes uniformly. Both of microstructure and residual compressive stress are propitious to fatigue life