【摘要】 本文通过滑移爆轰试验研究了低载荷下(2~4GPa)高纯铜试样的层裂行为。对爆轰后的层裂试样进行了金相和EBSD分析。金相分析结果表明:在滑移爆轰试样主层裂面上存在层裂面分叉的现象,在边部存在与主层裂面垂直的层裂面。在微结构相同的试样中,随着冲击压力的增大,孔洞分布区域的面积增大、微孔洞的贯通现象也更加明显。EBSD分析的结果表明:爆轰试验导致试样层裂区域晶粒尺寸减小,晶粒沿垂直于冲击应力的方向被拉长。爆轰时由于冲击压力极高,变形时间短(10μs),在试样中形成变形孪晶。层裂试样中微孔洞多在多条一般大角度晶界构成的三叉节点处形核,多条Σ3晶界构成的三叉节点对损伤形核有抵抗作用。损伤多形核于泰勒因子(TF)值较高的晶粒与其他晶粒构成的晶界上。TF值较高的晶粒中损伤的面积更大些。更多还原

【Abstract】 Suites of sliding detonation experiments have been conducted to assess the spall behavior of high purity copper samples at low pressures(2-4GPa).Metallographic and EBSD analysis have been performed on the recovered samples.Spall plane branching was found in the main spall plane of damage samples.Spall plane perpendicular to the main spall plane was found in the lateral of some samples.For similar microstructure,the area of voids existed increase with the increasing of shock stress,and the coalescence of voids also assume the trend of escalation.Results from EBSD analysis show that the grain sizes have decreased and the grains were elongated along the direction perpendicular to the shock stress in the spall area.The presence of deformation twins most likely due to the high impact stress and short deformation time during detonation.Triple junctions formed by two or more general high angle boundaries are the preferred locations for intergranular damage localization.Voids prefer to nucleate in the grain boundaries formed by grain with high Taylor Factor(TF)and other grains.The damage areas in the grain with high TF are more serious.更多还原