高纯铝硅钎料的高温力学性能和显微组织特征
High-Temperature Mechanical Properties and Micro Organizing Character of High Purity Al-Si filler
史平安，何建军，王军，李盛和
点击：4565次 下载：0次
作者单位：1. 中国工程物理研究院总体工程研究所; 2. 表面物理与化学国家重点实验室
中文关键字：铝硅钎料，高温力学性能，显微组织，焊接缺陷
英文关键字：Al-Si filler metal；High temperature mechanical property；Microstructure；Welding faults
中文摘要：为了降低铍焊缝的缺陷、提高焊接接头的强度，本文针对所研制的高纯铝硅钎料，采用材料高温拉伸试验、SEM扫描、能谱分析等分析手段，分析研究了铝硅钎料的高温力学性能、组织特征和钎焊接头的成份分布，探讨了焊接缺陷形成机制。研究结果表明，冷却速率通过改变初生α-Al相和共晶β-Si相的形态进而影响到材料的力学性能，冷却速率增加，共晶β-Si相变细，相间距减小，材料的热塑性提高。焊缝部位的SEM及能谱分析结果显示，裂纹部位的C、O、Ca等杂质元素含量偏高，尤其是BeO在晶界的偏析严重，这些脆性相在晶界处聚集，导致局部区域塑性降低。
英文摘要：In order to improve the welding quality and decrease defects in laser welding-brazing of beryllium. The mechanical properties of high purity Al-Si filler metal were evaluated by high-temperature tension experiments, the microstructure characteristic and component distributing and interfacial reaction of the joints were analyzed by SEM and EDS. The mechanism of weld crack was investigated in the process of laser welding-brazing of beryllium. It has been found that the grain size of β-Si dendrite become finer and more uniform with increase of cooling rate, and all of those make the tension strength, thermal plasticity improved. High content of C、O、Ca were detected in the crack band gathered at crystal boundary, especially BeO existed in micro-cracks and their segregation and aggregation resulted in micro-cracks.