分析了在强热冲击下2A12铝合金材料内部的微观损伤特征.采用激光在圆片试样中心打孔方式,来实施对铝合金强热冲击实验.应用扫描电子显微镜,观察了激光穿孔附近纵、横截面上的金相组织,并得到了热影响区内材料损伤的显微照片.这些电镜图片显示出穿孔周围有微孔洞群、沿晶开裂的微裂纹、三叉晶界处萌生的微孔、破碎状裂隙带和白色亮条等微观损伤的复杂形态.分析指出激光穿孔强热冲击所形成的热波对材料作用是产生这些微观损伤的主要原因.%The characterization of microdamage in 2A12 aluminum alloy materials after intense thermal shock was analyzed. The intense thermal shock for the aluminum alloy was experimentized by using laser drilling on the center of circle plate specimens. The metallurgical structure on the cross and longitudinal sections near the laser drilling hole of specimens was observed, and the micrographs of the material damage in heat affected zone was obtained by means of SEM. These micrographs reveal more complex conformation of microdamage around the drilling hole, such as microvoid group, extending intergranular microcrack along grain-boundary, growing cavity at trifurcate grain-boundary, fragmentized fissure zone, whitely shiny strip. The analysis indicated that a dominant cause to bring such microdamage is thermal wave effect on aluminum alloy material which generates from intense thermal shock when laser drilling.
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