Effects of Zn, Zn-Al and Zn-P additions on melting points, microstructures, tensile properties, and oxidation behaviors of Sn-40 Bi lead-free solder were investigated. The experimental results show that the addition of these three types of elements can refine the microstructures and improve the ultimate tensile strength(UTS) of solder alloys. The fractographic analysis illustrates that ductile fracture is the dominant failure mode in tensile tests of Sn-40Bi-2Zn(SBZ)and Sn-40Bi-2Zn-0.005Al(SBZA) specimens, while brittle fracture is the controlled manner in Sn-40Bi-2Zn-0.005P(SBZP) and Sn-58 Bi solders. XPS analysis indicates that trace amounts of both Al and P additives in solder can improve the antioxidant capacity, whereas only the additive of Al in solder can reduce the thickness of oxidation film.
Xiaojing WangYanlai WangFengjiang WangNing LiuJianxin Wang
采用激光熔覆技术在H13钢表面制备Fe Co Cr Cu Ni Mo VSi B高熵合金涂层.借助SEM和XRD等分析测试方法研究激光熔覆高熵合金涂层的微观组织形貌、相结构、显微硬度和耐磨性.研究表明:制备的Fe Co Cr Cu Ni Mo VSi B高熵合金涂层显微硬度最高可达740HV;其微观组织主要由树枝晶组成,相结构为FCC+BCC+简单立方结构;涂层具有良好的耐磨性能,主要的磨损机理为剥层磨损.
