Study On Microstructure And Properties Of N-SiC_p/ZK61 Magnesium Matrix Composites Wire

N-SiCP particles with a nominal size of 100 nm and ZK61 alloy powder with a nominal size of 40 μm were used as raw materials.After the powder was mixed by ball milling,a combination of reciprocating extrusion and forward extrusion was used to prepare a magnesium-based composite wire with a diameter of Φ1 mm.Comparatively studied the influence of different mass fractions of N-SiCp particles on the structure,texture and mechanical properties of magnesium-based composite wires;The electrochemical properties and friction and wear properties of the wire were tested,the influence of N-SiCP on the corrosion resistance and friction and wear properties of the composite wire was studied,and the electrochemical corrosion behavior and friction and wear mechanism were discussed.The influence of different heat treatment processes and N-SiCp content on the microstructure and mechanical properties of N-SiCp magnesium-based composite wires was compared and studied.The main conclusions are as follows:(1)RE-4p-EX-xN-SiCp/ZK61(x=0,1,2,3,%)composite wire has a uniform structure without obvious holes,cracks and other defects.The structure is composed of α-Mg,MgZn2 phase and N-SiCP particles.The reinforcement N-SiCp is well combined with the matrix.When the content of N-SiCP reaches 3%,there is a little agglomeration of N-SiCp.(2)Compared with RE-4p-EX-ZK61,with the increase of N-SiCP content,the tensile strength and yield strength of RE-4p-EX-xN-SiCP/ZK61(x=0,1,2,3,%)composite wire have been improved to varying degrees,but the elongation has shown a decreasing trend.When the N-SiCp content is 3%,the tensile strength,yield strength and elongation of the wire are 325 MPa,288 MPa and 4.6%,respectively.(3)Since N-SiCP is well combined with the magnesium alloy matrix and no chemical reaction occurs,the addition of N-SiCP has no significant effect on the corrosion resistance of the composite wire.(4)Under the condition of dry sliding friction at room temperature,the addition of nano-particle N-SiCP can improve the wear resistance of RE-4p-EX-ZK61,and as its content increases,the wear resistance of the composite material is gradually enhanced.(5)With the increase of load and sliding speed,the N-SiCP particles are more likely to fall off during the friction process,and the wear surface morphology of RE-4p-EX-3%N-SiCP/ZK61 is always rougher than that of RE-4p-EX-ZK61.The wear volume gradually increases,but the wear rate of RE-4p-EX-3%N-SiCP/ZK61 is always lower than that of RE-4p-EX-ZK61.The addition of N-SiCP particles can significantly improve the wear resistance of the material.(6)Compared with the extruded ZK61 alloy,the elastic modulus,yield strength and tensile strength of the RE-4p-EX-xN-SiCP/ZK61 composite have been significantly improved,while the elongation has decreased.After solution treatment,the tensile strength of RE-4p-EX-xN-SiCP/ZK61(x=0,1,2,3,%)composite material wire changes in the same way as the hardness.With the increase of N-SiCP content,the tensile strength and yield strength tend to increase.(7)The hardness of the RE-4p-EX-xN-SiCP/ZK61 composite material increases with the increase of the aging time,and an obvious aging peak appears at 16 h,and then the hardness begins to decrease.Solid solution at 420℃ for 2 h and aging at 180℃ for 16 h is the best heat treatment process system for composite materials.Under this process condition,the second phase presents a needle-like distribution and the composite material has the highest hardness.