Deformation Of Zinc, Copper And Titanium Alloy Creep Behavior Of Their Organizations And Performance

A serial of Zn-Cu-Ti,Zn-Cu-Ti-Cr,Zn-Cu-Ti-Mn,Zn-Cu-Ti-Mg,Zn-Cu-Ti-Al alloys were parepared by melting, casting and extruding. This eassay studied the microstructure of the alloys of different compositions with the help of XRD,DSC,SEM,TEM,EDS and so on, revealed the alloying effects on alloys' mechanical properties, and also estabilished the equation of recrystallization and creep at high temperature, discussed the alloys' recrystallization mechanism and creep mechanism. The following results were obtained:(1) Zn-0.5～3.0Cu-0.1～0.3Ti alloy melting pointis is between 419.7℃and 422.6℃; Wrought Zn-Cu-Ti alloy is constituted of phase,εphase and TiZn15 phase. During hot extrusion process at 250℃, dynamic recrystallization occurres and the second phase inhibits the recrystallization grain growth.(2) Strength and elongation of the alloys increases with the increase of Cu and Ti elements, but elongation decreases once Ti% is above 0.2%. Trace Cr,Mn,Mg,Al increases the strength of Zn-1.0Cu-0.2Ti alloy; The tensile strength of Zn-1.0Cu-0.2Ti-0.05Mg is up to 280MPa.(3) The recrystallization temperatures of Zn-1.0Cu-0.2Ti alloy and Zn-1.0Cu-0.2Ti-0.1Cr alloy are 230℃and 260℃respectively. The ecrystallization grain growth activation energy is 49.96 KJmol-1. Grain growth equation of the Zn-1.0Cu-0.2Ti alloy is established: D2= 21.47+533851.14te (6009.14/T)(4) The creep activation energy of Zn-1.0Cu-0.1Ti alloy at high temperature is 83.7 KJmol-1. Zn-1.0Cu-0.1Ti alloy constitutive equation can be expressed as:ε= 5.32×10-3σ5.10exp(-83720/RT). The main mechanism of high temperature creep is controlled mainly by diffusion mechanisms. the main mechanism is the sliling and climbing mechanism of dislocation during the creep period at room temperature. Zn-1.0Cu-0.2Ti-0.1Cr alloy shows a better creep property than the Zn-1.0Cu-0.2Ti alloy at 25℃.