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.
出处
《热加工工艺》
CSCD
北大核心
2012年第19期20-22,共3页
Hot Working Technology
