激光修复TC4钛合金显微组织与力学性能（英文）

发布时间：2018-04-15 05:16

  本文选题：激光修复 + 钛合金　； 参考：《稀有金属材料与工程》2017年07期

【摘要】：以低氧TC4粉末为熔覆材料,采用激光修复技术制备了TC4钛合金面修复试样,对比研究了锻件和修复试样(沉积态)的显微组织和力学性能。结果显示:修复试样的组织宏观上分为锻件基材区、热影响区和激光沉积区,3个区域中热影响区的显微硬度最高,沉积区和锻件基材的显微硬度相当。锻件试样的强度及塑性均略高于修复试样,同时发现40%修复试样(即拉伸试样承受载荷部位横截面上沉积区所占的面积分数为40%)的强度略低于50%修复试样,塑性则高于后者。表明采用低氧TC4粉末为熔覆材料时,有利于修复试样沉积区和基材区强度和塑性的匹配,从而提高修复试样的综合性能。对拉伸断口进行扫描电镜观察发现,锻件试样拉伸失效后断口呈现出典型的韧性断裂特征,而修复试样的断口则表现复杂,从沉积区到锻件基材区呈现出解理台阶到韧窝的连续变化特征,同时断口形貌与显微组织呈现出很好的对应关系。
[Abstract]:Using low oxygen TC4 powder as cladding material, the surface repair specimens of TC4 titanium alloy were prepared by laser repair technique. The microstructure and mechanical properties of the forged and repaired samples (deposited) were compared.The results show that the microstructure of the repaired specimen can be divided into three parts: forging base area, heat affected zone and laser deposition zone. The microhardness of the heat affected zone is the highest, and the microhardness of the deposition area is the same as that of the forging substrate.The strength and plasticity of the forgings are slightly higher than those of the repaired specimens, and it is found that the strength of 40% of the repaired specimens (i.e. the area fraction of the deposition area on the cross section of the tensile specimens subjected to load is 40%) is slightly lower than 50% of the repaired specimens, and the plasticity is higher than the latter.The results show that using low oxygen TC4 powder as cladding material can improve the comprehensive properties of the repaired samples by improving the strength and plasticity matching between the deposition zone and the substrate zone.Scanning electron microscopy (SEM) observation of tensile fracture shows that the fracture surface of forgings shows typical ductile fracture characteristics after tensile failure, but the fracture surface of repaired specimen is complex.The continuous variation of cleavage step to dimple was observed from the deposition area to the base material area of forgings. At the same time, the fracture morphology showed a good corresponding relationship with the microstructure.
【作者单位】： 西北工业大学凝固技术国家重点实验室;西安航空发动机(集团)有限公司;
【基金】：National Natural Science Foundation of China(51475380) Research Fund of the State Key Laboratory of Solidification Processing(NWPU),China(99-QP-2014)
【分类号】：TG146.23;TG665
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本文编号：1752677