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针对铸造镁合金显微硬度较低、抗腐蚀性能较差的问题,采用激光冲击强化处理方法,以AM50铸造镁合金为对象,研究激光冲击强化对深度方向晶粒结构、显微硬度和残余应力的影响。研究结果表明,经过单次冲击强化后,镁合金表层的显微硬度值、残余压应力值均有明显改善,在冲击强化层,原始粗晶明显细化、表层显微硬度值提高19%、残余压应力达到-225 MPa;同时显微硬度提高区域的深度,晶粒细化层及残余压应力层的深度也明显增大;并且当冲击次数增加到2次时,显微硬度、晶粒尺寸和残余应力得到进一步改善。
Aiming at the problem of low microhardness and poor corrosion resistance of cast magnesium alloy, laser shock strengthening method was used to study the effects of laser shock strengthening on the grain structure in the depth direction, microhardness and residual stress Impact. The results show that after a single impact strengthening, the microhardness and residual compressive stress of the magnesium alloy surface layer are obviously improved. In the impact strengthening layer, the original coarse crystal is obviously refined, the surface microhardness value increases by 19% The residual compressive stress reaches -225 MPa; at the same time, the depth of the microhardness increasing region and the depth of the grain refinement layer and the residual compressive stress layer also increase obviously; and when the impact times increase to 2 times, the microhardness, The size and residual stress are further improved.