The article contains the results of tests on a laser-processed eyelet of undercarriage drag strut to increase its fatigue strength. Laser processing concentrated on both sides around the hole of eye for connecting the undercarriage drag strut caused that the material in this area withstood more than twice the number of load cycles established for this material. In order to determine the reasons for the increase in fatigue strength, residual stresses in laser-treated LT areas and in the base metal BM located between melted paths were determined, using the nanoindentation test and Williamson Hall method. The modified Williamson Hall analysis of XRD patterns was also used to determine the dislocation density in both areas. The results indicate that high residual tensile stresses occur in melted areas and in base metal located between melted paths occur high residual compressive stresses. A large increase in hardness and elastic properties, dissolution of non-metallic inclusions, as well as large solid solution and sub-grain strengthening contributed to the high fatigue resistance of the melted areas.

该文章包含在起落架减振支柱的激光加工孔眼上增加其疲劳强度的测试结果。激光加工集中在眼孔的两侧，用于连接起落架拖曳支柱，导致该区域的材料承受的载荷次数是为此材料确定的载荷循环次数的两倍以上。为了确定疲劳强度增加的原因，使用纳米压痕测试和Williamson Hall方法确定了激光处理的LT区域和位于熔融路径之间的贱金属BM中的残余应力。改进的X射线衍射图的Williamson Hall分析也用于确定两个区域的位错密度。结果表明，高残留拉伸应力发生在熔融区域，而位于熔融路径之间的母材中则发生高残留压缩应力。硬度和弹性性能的大幅提高，非金属夹杂物的溶解以及较大的固溶体和亚晶粒强化都有助于提高熔化区域的抗疲劳性。