Study On Microstructure And Properties Of Laser Forming Specimen Of Alloy Powder Coated By Organic

The purpose of this paper is to solve oxidation of the iron-base self fluxing alloy powder in laser rapid forming process under atmospheric environment in. by laser rapid forming technology forming different specimens, and to study properties of macro morphology,hardness,tensile strength,fatigue,phase composition,microstructure and corrosion resistance.(1) We find that the added organic of cladding layer is smooth with metallic luster,section almost no defects,cladding layer without organic is covered oxide,the defects of section rate up to about 4%.(2) Organic,coating the surface of the alloy powder particles,can produce atmosphere of reducibility,leading to oxygen consumption,protecting the molten pool,reducing the burning of alloy elements.(3) Iron-based martensitic stainless steel alloy powder with addition of organic,to a certain extent,the loss of alloying elements decreases, and the effect of alloying elements increases,which not only increases the dispersion strengthening phase, but also causes the alloy element segregation,so value of Rockwell hardness increase by about 5.3% with wear resistance improving,but the hardness range and standard deviation become large,Similarly,iron-based austenitic stainless steel alloy powder with addition of organic,its microhardness increase by about 21% with hardness range and the standard deviation become large.(4) With elements loss of laser rapid forming of adding organic reduce,various alloy elements cause dispersion strengthening and solid solution strengthening effect will be strong,and organic can the refine grain,which improve the microstructure of specimens,and reinforce specimens and shaping toughnes. Organic will also reduce defects of laser rapid forming specimen,reducing the chance that the micro cracks.Iron-based martensitic stainless steel alloy powder with addition of organic,its specimen average tensile strength and fatigue strength increase by about 16%,the martensite diffraction peak increased,and corrosion resistance is enhanced. Iron- based austenitic stainless steel alloy powder with additon of organic,the specimen average tensile strength and fatigue strength increase by about 15.6% and 38%. Austenitic diffraction peak increased,corrosion resistance is enhanced.