Research On Continuous Extrusion Process Of Zinc-aluminum Alloy Pipe

Zn-Al alloy is a kind of alloy which has low melting point and high strength.It is widely applied into fields such as mining metallurgy,light industry,ship building,chemical industry,machinery equipment etc.The main characteristic of Zn-Al alloy includes high strength and hardness,good damping,low friction coefficient,low temperature rise during friction and good abrasion resistance.Meanwhile,it caused less pollution and has low energy consumption,rich raw materials resources,low manufacturing cost etc.The continuous extrusion technology is regarded as a revolution of the non-ferrous metal processing because it has changed the friction from resistance to power,improved the production efficiency,also saved energy and the cost of production.Zn-Al alloy tube produced by the Conclad continuous extrusion technology not only take the advantage of the excellent characteristics of Zn-Al alloy,but also combine the advantages of continuous extrusion technique such as high efficiency,energy saving,short process,near the end,lower cost.And through the severe plastic deformation characterized by the tangential type continuous extrusion,the grains are smaller and the microstructures are more homogeneous.It has a large market potential for application.This thesis is mainly about the study of hot forming performance of components in Zn-10%Al-2%Cu alloy.Constitutive equation of the critical flow stress of Zn-Al alloy was derived after Gleeble thermal simulation experiment and it is the reference for Zn-Al alloy tube continuous extrusion forming.And then the process parameters range is selected.The process parameters are extrusion velocity and temperature.The die of continuous extrusion forming is designed based on the equipment condition and the need.The process parameters of Conclad technology of Zn-Al alloy were obtained through experiments.The temperature of die cavity is 260?300?.Preheating temperature of raw material is 240?260?.The extrusion velocity is controlled at 1?4r/min.Meanwhile,it can be comfirmed that recrystallization phenomenon happened in Zn-Al alloy after hot deformation through microstructure analysis andthe results of Gleeble thermal simulation.