【摘要】 采用SIMA方法制备半固态坯料。以7A09铝合金铸锭为原材料,采用正挤压和等温处理工艺制备半固态坯料,并对坯料做金相观察,确定实验条件下制备半固态坯料的参数。实验中影响半固态坯料制备的主要因素有挤压比、等温温度、保温时间。研究结果表明:挤压比7、模温300℃、铸态试样加热450℃且保温30 min、较低的挤压速度是坯料预处理过程优选的参数;在等温处理过程中,加热温度为617℃、保温19 min可以获得理想的半固态组织。更多还原

【Abstract】 SIMA was adopted to make semi-solid billet.7A09 cast ingot of Ф33 mm×15 mm was used to make billet by direct extrusion and isothermal treatment.The billet was observed by metallographic method in order to determine the parameters for making the semi-solid billet.The main factors in this experiment were extrusion ratio,isothermal temperature and holding time.The results show that the preferred values are extrusion ratio of 7,mould temperature of 300 ℃,cast condition sample’s heating temperature of 450 ℃ and holding for 30 min and lower extrusion velocity in the process of billet pretreatment.In the process of isothermal treatment,heating temperature of 617 ℃ and holding for 19 min can acquire perfect semi-solid microstructure.更多还原