冷金属过渡电弧增材制造强制限位冷却工艺研究

Forced Limit Cooling Process for Cold Metal Transfer Arc Additive Manufacturing

目的针对冷金属过渡(CMT)电弧增材制造过程中不稳定气流环境造成的熔池流动不均、墙体成形异常以及墙体内部气孔过多和晶粒粗大的问题,研究增强沉积墙体组织性能的工艺。方法开发了CMT电弧增材制造强制限位冷却工艺,通过控制电弧增材制造的沉积区间和凝固过程,来改善沉积墙体的结构性能。结果沉积墙体平均沉积速度由0.120 mm/s升到0.149 mm/s,材料利用程度由78.2%升到83.2%,孔隙率由2.15%降到1.06%,平均晶粒度由15.7μm降到13.3μm。同时提高了沉积墙体的韧性,沉积墙体横向平均极限拉伸强度由157 MPa升到179 MPa。结论CMT电弧增材制造强制限位冷却工艺制造的沉积墙体在沉积速度和材料利用程度方面有了相应提高,同时强制限位冷却工艺改善了沉积墙体的结构性能,这对增材制造具有一定的指导意义。

The work aims to study a process to enhance the structural performance of deposited walls to solve the problems of uneven flow of the molten pool,abnormal wall forming,excessive pores and coarse grains in the wall caused by unstable airflow environment during the cold metal transfer(CMT)arc additive manufacturing process.A forced limit cooling process for CMT arc additive manufacturing was developed to improve the structural performance of the deposited wall by controlling the deposition interval and solidification process of arc additive manufacturing.The average deposition rate of the deposited wall increased from 0.120 mm/s to 0.149 mm/s.The material utilization increased from 78.2% to 83.2%.The porosity rate dropped from 2.15% to 1.06%.And the average grain size dropped from 15.7μm to 13.3μm.At the same time,the toughness of the deposited wall was improved.The transverse average ultimate tensile strength of the deposited wall rose from 157 MPa to 179 MPa.The deposited wall after the forced limit cooling process of CMT arc additive manufacturing has a corresponding increase in deposition speed and material utilization.At the same time,the forced limit cooling process improves the structural performance of the deposited wall,which has certain guiding significance for additive manufacturing.