TC17钛合金线性摩擦焊工艺研究及显微组织分析

Study on Linear Friction Welding Process and Microstructure Analysis of TC17 Titanium Alloy

摘要:

采用不同焊接频率（20-50Hz）、振幅（1-4mm）、摩擦压力（32-96MPa）对TC17(α+β)/TC17(β)钛合金进行线性摩擦焊试验研究，分析了不同焊接参数对钛合金线性摩擦焊接头质量的影响及接头不同区域显微组织演变规律。结果表明：热输入不足时，无法得到良好的焊接接头，其他焊接工艺参数不变时，随着单一参数的增加，热输入量迅速升高，焊接过程达到稳定状态，参数对焊接过程及接头质量的影响较小。TC17(α+β)/TC17(β)钛合金线性摩擦焊接头焊缝区域在焊接过程中发生了明显的相变及动态再结晶，形成亚稳定β相；两侧热力影响区由于受到热力耦合的作用，等轴及板条状α相沿着振动方向拉长，针状次生α相完全溶解。

Abstract:

The linear friction welding behavior of TC17(α+β)/TC17(β) was investigated using several different processing conditions of frequency(20 to 50 Hz), amplitude (1 to 4 mm), friction pressure(32 to 96 MPa). The experimental research analyzed the influence of different welding parameters on the quality of LFWed joints, the microstructure of different regions of joints. The results showed that when the heat input is insufficient, a good welding joint can not be obtained. When other welding parameters remain unchanged, with the increase of single parameter, the heat input increases rapidly, the welding process reached a stable state, and the influence of parameters on the welding process and joint quality was small.?It was observed that phase transition and dynamic recrystallization were occurred in the weld region during the welding process, and finally formed a metastable β phase after weld; the equiaxed and lath α phase were elongated along the vibration direction, and the intergranular needle-like secondary α phase was completely dissolved in both sides of the thermo-mechanically affected zone because of undergoing thermal coupling.