中文摘要：

对渗铝、渗铝后强化、强化后渗铝的K417合金试件分别进行振动疲劳试验。试验结果表明,相对于渗铝处理,强化后渗铝试样的疲劳强度提高了50%,而渗铝后强化试样的疲劳强度提高了30%,这说明渗铝与激光喷丸强化复合工艺可以提高材料的疲劳性能,且强化后渗铝效果更好。采用X射线衍射（XRD）、扫描电子显微镜（SEM）和透射电子显微镜（TEM）分析激光喷丸强化与渗铝复合工艺顺序对材料力学性能的影响,讨论了疲劳性能的改善机理。结果表明,激光喷丸强化促进了渗铝过程,生成大量柱状晶,渗层厚度增加,渗层与基体的结合更加紧密,从而有效提升疲劳性能;而渗铝后强化主要对渗层表面进行了形变强化,疲劳性能的提升有限。

英文摘要：

Vibration fatigue tests were performed on aluminizing, LSP after aluminizing,aluminizing after LSP K417 alloy specimen respectively. The results showed that, compared with that treated by aluminizing only, the fatigue strength of specimen treated by aluminizing after LSP was improved by 50% and that treated by LSP after aluminizing was improved by 30%. It showed that the composite technology of LSP and aluminizing can improve the fatigue performance, and the composite technology of aluminizing after LSP can improve more effectively. The influence of different technology order to mechanical properties were investigated by X-ray diffraction （XRD）, scanning electron microscopy（SEM） and transmission electron microscopy（TEM）. The improvement mechanism of the fatigue performance was discussed. The results indicate that the LSP can promote the process of aluminizing. The combination of aluminizing layer with matrix is more close and a large number of columnar crystals formed in the surface treated by aluminizing after LSP, which lead to the thickness of aluminizing layer increase, and then the fatigue performance improved. But the LSP after aluminizing only affects the surface strengthening, and the improvement of fatigue performance is limited.