关键词: 喷射沉积, 半固态, 轧制, 显微组织

Abstract:

Semisolid rolling of spray-deposited 7050 aluminum alloy was carried out at 560～620 ℃,and the effects of remehing temperature on grain size and second-phase distribution of the alloy were investigated by means of SEM ,EDS and XRD.Moreover,the influences of remehing temperature and thickness reduction ratio on the mi-crostructureof the strips were explored,and the feasibility of semisolid rolling was evaluated.The results show that(1)the activation energy for the grain growth of spray-deposited 7050 aluminum alloy is 70.5 kJ/mol;(2)when the remehing temperature inereases from 560 to 620 ℃,the coarsening rate and the liquid fraction of spray-deposited 7050 aluminum a110y respectively increase from 1.16 to 76.06  μm³ /s and from 3.7% to 64.1% ;(3)the distribu。ti0n and amount 0f second-phase particles inhibit the coarsening of spray-deposited 7050 aluminum alloy; (4)the optimum remelting temperature for the semisolid rolling is 590℃ ;and(5)the rolling deformation plays its role in tenns of eliminating pores,breaking grains and accelerating dynamic reerystallization.

Key words: spray deposition, semisolid, rolling, mierostructur