Research On The Organization And Performance Of TiC_P/ZA35 Composites Prepared By In Situ Reation Spray Forming

There are some disadvantages with Zinc-Aluminium alloy,such as low working temperatureand and poor corrosion resistance and so on.In order to improve the comprehensive properties of Zinc-Aluminium alloy.In this paper,ZA35 is used as basis alloy.TiCp/ZA35 composites were prepared with situ reaction and spray deposition process.Thermodynamic calculation was carried out in the Al-Ti-C reaction system.The extruded and heat treated microstructures of TiCp/ZA35 composites were analyzed.The mechanical properties,corrosion resistance,damping properties and wear resistance of the composites were tested and analyzed.(1)The experimental result shows that Gibbs free energy of TiC produced is lowest in the Al-Ti-C reaction system,TiC is the most stable phase in thermodynamics.(2)Grains size of spray forming TiCp/ZA35 composites are fine,TiC particles is distributed uniformly in the matrix.After hot extrusion,voids are decreased in the microstructure of the composites,the denity of the composites are increased.When extrusion presure is 430 MPa,ereusion temperature is 285 ?,extrusion ratio is 12 and extrusion rate is 8 mm s-1 in the hot extrusion process parameters,the mechanial properties of TiCp/ZA35 composites in situ reation spray forming is the best.In this condition,the tensile strength of hot extruded zinc matrix composites is 485 MPa and the elongation is about 9.53%.(3)After solution and aging treatment,the microstructure is fine equiaxed grain.The distribution of TiC reinforcement in the tissue is uniform,and there is no segregation phenomenon.After solid solution at 350 ? for 4 h and aging at 150 ? for 6 h of TiCP/ZA35 composites,there are more dispersed second-phase pinned in grain boundary and within grains.The lowest slof-corrosion electrical current density of solid solution at 350? for 4 h andsolid solution at 350 ? for 4 h and aging at 150 ? for 6 h of TiCP/ZA35 composites is 0.005m·cm-2.Its corrosion resistance is greatly reduced compared with untreated samples.(4)When the frequency is 4 Hz and the temperature is 100? the internal friction value of solid solution at 350 ? for 4 h and aging at 150 ? for 6 h of TiCp/ZA3 5 composites is 0.087,it is 1.47 time than the sample without heat treatment.After heat treatment,damping of material increases due to the internal friction of dislocation and reinforced TiCp/ZA35 matrix interface.(5)The wear rate of solid solution at 350 ? for 4 h of TiCp/ZA35 composites is 5.47,the wear rate was 5%lower than he sample which has no heat treatment under 360#sandpapers.The wear rate of aging at 150 ? for 6 h of TiCp/ZA35 composites decreases first and then increases.The wear rate of aging 6 h was the lowest,it is as low as 4.56 mg cm-2,which is the best wear performance...