强激光冲击波作用下Al2O3陶瓷材料的断裂特征

使用激光冲击对Al2O3陶瓷进行了冲击试验，并通过扫描电子显微技术，对陶瓷材料在强激光冲击下的断口形貌进行了分析．发现随激光能量的变化。陶瓷出现不同的断裂特征．在高能量激光冲击下，试样宏观上出现中心裂纹，其微观主要仍以沿晶断裂和穿晶解理所形成的脆性断裂模式为主；但在激光能量降低到一定程度的情况下，脆性陶瓷材料在拉伸波作用下出现锥形断裂，而微观上也出现一定的塑性滑移特征，主要表现为晶界处出现大量的滑移线；在更低能量下陶瓷未出现破裂，硬度分析结果显示具有微观塑性变形强化现象．

Fracture characteristic of Al2O3 ceramics by strong laser shock processing

Ceramic of Al_2O_3 was processed by laser shock processing(LSP) under different energies.The fracture morphology formed by strong LSP was studied with scanning electron microscopy(SEM).It was found that different features in the ceramic materials showed up under different laser energies.The brittle fracture consisted of intergranular fracture and cleavage fracture was the main mode under high-(energy) laser shocking and the radial fracture was formed.When the laser energy was reduced to an appropriate level,subulate fracture developed from tensile-stress induced by reflected wave,and plastic deformation occurred.With the energy reduced the feature of micro-plastic deformation remained under the lower energy.