材料科学与工程学院知识库

An orthogonal experiment with four factors and three levels is designed to investigate the manufacturing technology and properties of BrAlFe4 aluminium-bronze parts by selective laser melting. Through orthogonal experiment and signal-to-noise ratio analysis, the optimal technological parameters are as follows: laser power 450W, scanning speed 1700mm/s, thickness 30 mu m, scanning space 60 mu m. The density of aluminium-bronze parts can reach a maximum of 98.94%. The micro-structure of aluminium-bronze parts is network dendritic structure in which the alpha phase and (alpha+ gamma(2)) precipitated phase are uniformly distributed. The micro-hardness can reach 384.1HV,90% higher than traditional casting parts (200HV). The surface roughness of aluminium bronze formed directly by Selective Laser Melting technology is 8.911 mu m. Through the tensile test at room temperature, the tensile strength of aluminium bronze part reaches 575-595MPa, which is higher than casting parts (490-540MPa). And it's a typical brittle fracture, from which clear river patterns and cleavage steps can be observed.