高Si多组元铝镁焊料冲击韧性损失研究

发布时间：2018-04-22 00:30

本文选题：铝镁焊料 + 硅焊料　；参考：《稀有金属》2017年11期

【摘要】：解理断裂通常发生在体心立方金属和密排六方金属,面心立方的铝合金极少发现解理断裂。通过金相显微镜(OM)、扫描电镜(SEM)和能谱分析(EDS)等分析方法和冲击试验研究了Si对铸态多组元Al-5Mg-Mn-Cr-Ti焊料断裂韧性损失,着重研究了Si致焊料解理断裂机制。研究发现,当Si含量大于0.5%时面心立方的铝镁焊料中有解理断裂。随焊料中Si含量的增加,Mg2Si金属间化合物相增加,Mg2Si在晶界析出。Mg2Si相室温延展率几乎为零,硬度达HV 450,存在严重的室温脆性。焊料晶粒边界存在的Mg2Si相在应力作用下开裂形成初生裂纹,初生裂纹形成后扩展到相邻α-Al晶粒,α-Al发生断裂,该断裂属于裂纹形核控制断裂。同时Si聚积在α-Al密排面(111)面上,弱化密排面原子结合力,断裂沿α-Al密排面扩展。Si含量从0.15%增加到0.8%时焊料的冲击韧性急剧劣化,冲击功从35 J下降到14 J。断裂特征由延性断裂转变为脆性解理断裂为主的混合型断裂。Si增加,焊料断裂韧性损失严重,Si等于0.5%为焊料韧脆转变的临界点。
[Abstract]:The cleavage fracture usually occurs in the body center cubic metal and the dense six square metal. The cleavage fracture is rarely found in the aluminum alloy with the face centered cubic. The fracture toughness loss of the cast multi component Al-5Mg-Mn-Cr-Ti solder is studied by the metallographic microscope (OM), scanning electron microscope (SEM) and the energy spectrum analysis (EDS) and the impact test on the fracture toughness of the cast multi component Al-5Mg-Mn-Cr-Ti solder, which focuses on the study of Si. The cleavage fracture mechanism of solder is found. It is found that there is a cleavage fracture in the aluminum and magnesium solder of the center cube when the content of Si is greater than 0.5%. With the increase of Si content in the solder, the Mg2Si intermetallic compound increases, the temperature extension rate of the Mg2Si at the grain boundary precipitates at the.Mg2Si phase is almost zero, the hardness reaches HV 450, and there is a serious room temperature brittleness. The grain boundary of the solder is present. The Mg2Si phase cracked under stress and formed the primary crack. The initial crack was formed after the formation of the adjacent alpha -Al grain, and the alpha -Al broke, and the fracture belonged to the crack nucleation control fracture. At the same time, Si accumulated on the alpha -Al surface (111) surface, weakened the atomic binding force of the dense platoon, and the fracture along the alpha -Al surface expanded.Si content from 0.15% to 0.8%. The impact toughness is rapidly deteriorated, and the impact energy from 35 J to 14 J. has been decreased from the ductile fracture to the brittle cleavage fracture.Si, and the fracture toughness of the solder is serious, and the Si equal to 0.5% is the critical point of the ductile brittle transition of the solder.

【作者单位】：郑州机械研究所新型钎焊材料与技术国家重点实验室;
【基金】：国家国际科技合作计划项目(2015DFA50470) 河南省基础与前沿技术研究项目(162300410215)资助
【分类号】：TG42

【相似文献】