超声辅助CMT电弧增材制造TC4钛合金微观组织和力学性能研究

目的研究超声辅助对CMT电弧增材制造钛合金TC4微观组织及力学性能的影响。方法 CMT增材制造TC4钛合金的同时利用超声辅助设备进行振动辅助,采用不同的振动功率和不同的振动位置对增材后的TC4力学性能和微观组织进行对比分析。结果 600 W超声辅助振动基板时的钛合金试样成形美观,力学性能优异。水平方向上,抗拉强度平均值为952.7 MPa,伸长率平均值为7.46%;垂直方向上,抗拉强度平均值为905.83 MPa,伸长率平均值为11.03%,相较未施加超声振动增材试样的力学性能有明显提高。结论超声辅助的引入有效提高了熔池的深宽比,加快了熔池冷却速度,柱状晶尺寸也明显减小,针状马氏体数量增多,得到的钛合金力学性能和微观组织均良好。

Microstructure and Mechanical Properties of TC4 Titanium Alloy Made by UVA-CMT WAAM

The paper aims to study influences of ultrasonic-vibration assistance on microstructure and mechanical properties of CMT wire and arc additive manufactured TC4 titanium alloy. Ultrasonic assisted equipment was used for vibration assistance during CMT additive manufacturing of TC4 titanium alloy. The mechanical properties and microstructure of TC4 after additive manufacturing were compared and analyzed with different vibration powers and vibration positions. The resulting showed that the titanium alloy specimens had beautiful form and excellent mechanical performance with 600 W of ultrasonic-vibration assisted substrate. The average tensile strength in the horizontal direction was 952.7 MPa and the average elongation was 7.46%. The average tensile strength in vertical direction was 905.83 MPa and the average elongation was 11.03%. Compared with the samples without ultrasonic vibration additive manufacturing, the mechanical properties of the samples were significantly improved. The introduction of ultrasonic-vibration assistance effectively improves the depth to width ratio of the molten pool, accelerates the cooling speed of the molten pool, signifi-cantly reduces the size of columnar crystal, increases the number of acicular marten sites, and improves the mechanical properties and microstructure of TC4 titanium alloy.