等温处理工艺对触变压铸Al-30Si合金组织和力学性能的影响  

Effect of Isothermal Process on Microstructure and Mechanical Properties of Thixocasting Al-30Si Alloy

作　　者：张威[1] 阎峰云[2] 杨小建[1] 黄建余 杨国利 

机构地区：[1]中国船舶重工集团公司第十二研究所,陕西兴平713102 [2]兰州理工大学甘肃省有色金属新材料省部共建国家重点实验室,甘肃兰州730050 [3]海军驻兴平地区军代表室,陕西兴平713100 [4]陕西柴油机重工有限公司,陕西兴平713100

出　　处：《热加工工艺》2012年第19期20-22,共3页Hot Working Technology

摘　　要：研究了等温处理工艺对触变压铸Al-30Si合金(加入1wt%的磷盐变质处理)组织和力学性能的影响。结果表明,触变压铸组织中,初生硅的形貌较为圆整,针状的共晶硅消失。在高压下快速冷却,αAl来不及长大,颗粒大小分布是弥散的;在固相率较高共晶组织未全部熔化时,组织中的αAl以固相保留,形态为球状或近球状。在620℃,抗拉强度随保温时间的延长而增加。保温时间从80min增加到120min时抗拉强度从206MPa增大到220MPa,布氏硬度从92HB减小到84HB;在同一保温时间(100min)时,保温温度升高,抗拉强度先增大后减小,最大值为213MPa(620℃)。保温时间的增加或保温温度的升高,布氏硬度都呈现出减小的趋势。The effects of isothermal treatment process on microstructure and mechanical properties of thixocasting Al-30Si alloy （adding 1% phosphate modification） were studied. The results show that, the morphology of primary silicon is more spherical, and the needle-like eutectic structure is dissolved in thixocasting microstructure. As the αAl of the dendrite arm is no time to grow in quick cooling process, particle size distribution is dispersive. Under higher solid fraction and that part of the αAl not melting, the αAl retain solid phase and configuration is the spherical or near spherical shape. With the increasing holding time at 620 ℃, tensile strength raise. When holding time is increased from 80 min to 120min, tensile strength increases fi＇om 206 MPa to 220MPa, Brinell hardness decrease from 92 HB to 84 HB. In the corresponding holding time （100 min）, tensile strength first increase and then decrease with increasing holding temperature, the maximum of tensile strength is 213 MPa （620 ℃）. Brinell hardness decrease with increase of the holding time or rise of temperature.

关 键 词：Al—30Si 等温处理 触变压铸 微观组织 力学性能 

分 类 号：TG146.21[一般工业技术—材料科学与工程]