激光增材修复Ti60钛合金显微组织及力学性能

Microstructure and Mechanical Properties of Laser Additive Repaired Ti60 Titanium Alloy

摘要:

本文对整体叶盘材料Ti60钛合金进行激光增材修复，研究其显微组织及力学性能。结果表明，热影响区组织呈现由基体区双态组织向修复区网篮组织的过渡特征，平均宽度约为900 μm。修复区主要由贯穿多个沉积层的外延生长的柱状晶组成，柱状晶内为分布均匀的α相网篮组织。三个区域内均弥散分布着Ti3(Sn, Al)小平面相，尺寸相近，其形貌和含量却因制备工艺凝固速度的不同而差异明显。三个区域硬度相当。拉伸试样断口特征表明激光增材修复Ti60钛合金的断裂机制为混合型断裂，平均抗拉强度和屈服强度分别为992.4 MPa和916.6 MPa，优于Ti60钛合金锻件强度标准，断后伸长率和断面收缩率的平均值为8.5%和14.6%，与Ti60钛合金锻件标准相差不大，达到实际工程应用要求。

Abstract:

In this paper, the microstructure and mechanical properties of integral bladed titanium alloy Ti60 repaired by laser were studied. The results showed that the heat affected zone structure presents the transition characteristics from the Dual structure of the matrix area to the mesh basket structure of the repair area, and its average width is about 900 μm. The repair zone is mainly composed of columnar crystals growing epitaxially through multiple sedimentary layers, and the columnar crystals are uniformly distributed α phase mesh basket structures. Ti₃(Sn, Al) facet facies of similar size were dispersed in the structure of the three regions, but their morphology and regional content varied significantly due to the solidification speed of the preparation process. The three areas are equally hard. The fracture characteristics of tensile specimens show that the fracture mechanism of laser additive repaired Ti60 titanium alloy is mixed fracture. The average tensile strength and yield strength are 992.4 MPa and 916.6 MPa respectively, which are superior to the strength standard of Ti60 titanium alloy forgings, the average elongation and section shrinkage after fracture are 8.5% and 14.6% , which are similar to the standard of Ti60 titanium alloy forgings and meets the requirements of practical engineering application