Research On Mechanical Properties And Friction And Wear Properties Of Squeeze Casting Zinc-Aluminium

Mechanical properties and friction and wear properties of squeeze casting ZA27 alloy were studied in the paper. The influence of specific pressure and working parameters on mechanical properties and friction and wear properties of ZA27 alloy was investigated. The effect of heat treatment on friction and wear properties of squeeze casting ZA27 alloy was also studied.The results show that squeeze casting can remarkably improve the mechanical properties of ZA27 alloy. Compare with casting alloy, at room temperature, tensile strength of squeeze casting ZA27 alloy is increased about 18%, hardness about 24%, and elongation to 12.3%. With the increasing of temperature, tensile strength of ZA27 alloy is reduced and elongation is increased. Compared with copper alloy, ZA27 alloy has better performance whatever referred to friction coefficient and wear capacity, and squeeze casting. Squeeze casting further improve the friction and wear properties of ZA27 alloy.With the increasing of load, friction coefficient of squeeze casting alloy is reduced, wear capacity first is reduced and then increased. Friction and wear properties of alloy are better under when load is 100N. It shows that squeeze casting ZA27 alloy is suitable for heavy load conditions. The influence of sliding speed on friction and wear properties of ZA27 alloy is investigated. The results show that friction coefficient and wear capacity of squeeze casting ZA27 alloy are smaller under the condition of lower sliding speed. The friction and wear properties of squeeze casting ZA27 alloy and 45~# steel used to compose friction pairs better than that of squeeze casting ZA27 alloy and itself. It is because the binding energy on the friction surface is high and adhesive wear is serious when ZA27 alloy homogeneous composition is used to friction pairs. Squeeze casting ZA27 alloy is not suitable for dry friction conditions. The friction coefficient and wear capacity of ZA27 alloy is increased with temperature. Thus, at room temperature, friction and wear properties of squeeze casting ZA27 alloy were better under working parameters that sliding speed 200r/min, load 100N, friction pairs 45~# steel, lubricated by 20~# coarse oil, the friction coefficient is 0.054, and wear capacity is 0.0031g.The results of grain abrasion show that wear capacity are increased with abrasive grain size. And because the hardness of ZA27 alloy is less than 0.8 times hardness of abrasive grain, so the grain-abrasive area of squeeze casting ZA27 alloy is high-wear areas.The influence of heat treatment on friction and wear properties of squeeze casting ZA27 alloy is studied. The results show that it obtains better friction and wear properties after 320℃×8h water quench+250℃×6h aging. Friction coefficient is 0.0242 and wear capacity is 0.0020g.