磁控电弧熔敷微合金化铝基金属覆层的组织和性能研究

Research on Microstructure and Properties of Magnetic Control Arc Cladding Micro-alloyed Al Based Metal Coating

在装备铝合金损伤零部件熔敷成形修复过程中存在粗大结晶组织、热裂纹、缺陷多和力学性能差等问题,为了解决这些问题,在熔覆成型过程中引入了外加磁场,研究了外加纵向磁场作用于微合金化铝基金属丝材电弧熔敷成形过程的作用机理,及其对熔敷成形层的组织和性能的影响。结果表明：添加微量Sc和Zr元素可在铝基金属熔敷成形层制备过程中形成Al3Sc和Al3Zr高熔点质点,提高了熔敷成形层凝固过程中的形核率和形核速度,抑制了晶粒长大;外加纵向磁场通过影响电弧熔敷过程的热传递、熔滴过渡和液态金属流动等行为,改善了熔敷成形层的性能,为铝合金装备件的损伤修复提供了工艺基础。

There were many defects in the reparative process of aluminum alloy damaged parts, which were of coarse crystal structure, thermal cracks, many defect and poor mechanical properties. In order to solve those problems, the external magnetic field was introduced into the arc cladding forming process. The mechanism of longitudinal magnetic field acting on aluminum alloy cladding process and its influencing on the microstructure and properties of the cladding layer were studied.The results show that the addition of Sc and Zr trace elements can form the high melting point of Al3 Sc and Al3 Zr in the preparation process of aluminum based metal deposited forming layer, which can improve the nucleation rate and nucleation velocity and inhibit the grain growth in the solidification process of metal drop. The external longitudinal magnetic field can furtherly refine the microstructure of the deposited layer and improve the homogenization of the microstructure by influencing the behavior of the heat transfer, droplet transition and liquid metal flow, which can improve the properties of the deposited forming layer, and then, a technological basis for the repair of the damage of the equipment aluminum alloy was provided.