电磁搅拌对BT20钛合金激光沉积修复件组织和硬度的影响

Effect of Electromagnetic Stirring on Microstructure and Hardness of BT20 Titanium Alloy Laser Deposition Repair Parts

为了改善BT20钛合金激光沉积修复质量,引进电磁搅拌装置辅助激光沉积修复,通过改变磁场强度和搅拌速率的方法研究旋转磁场对激光修复件宏观形貌,微观组织和显微硬度的影响。结果表明,在电磁场的辅助作用下,修复件表面平整;α/β片层组织被机械折断,晶内α片层长度减小,但α片层厚度几乎不变,为0.4~0.5μm,晶粒被细化,显微硬度提高;随着磁场强度和搅拌速度的增加,修复件的显微硬度增加,在一定磁场强度和搅拌速率下修复区显微硬度趋于均匀。

In order to improve the laser deposition repair quality of BT20 titanium alloy, an electromagnetic stirring device was introduced to assist laser deposition repair, and the effects of rotating magnetic field on the macromorphologies, microstructures and micro-hardness of the laser repair layer were studied by changing the magnetic field intensity and magnetic stirring speed. The results show that under the effect of the electromagnetic field, the surface is flat. Meanwhile, the lamellar α/β in laser repaired zone is mechanically broken, the length of intra-crystalline α layers is reduced, but the thickness of α lamellar is almost the same, 0.4~0.5 μm, so the grains are refined and the microhardness increases. As the field intensity and the stirring speed increase, the micro-hardness of repaired parts also increases, while the micro-hardness of the repaired zone tends to be homogenization with certain parameters.