摘要
研究了添加不同含量的稀土元素对Al-Mg-Si汽车板材的时效特性及微观组织的影响。研究表明,提高时效温度可使合金达到硬度峰值的时间缩短,但硬度值较低。稀土可以细化晶界析出物,改善第二相的分布和形状,减小第二相沉淀质点的几何尺寸,增大粒子的分布密度且分布较均匀,加速了合金的时效过程,使得合金达到峰值时效的时间变短,硬度值有所提高。预时效可以形成细密、均匀、弥散的G.P.区,使得在随后的时效过程中形成高密度的强化相,减少自然时效的不利影响,提高合金的硬度。含有稀土的合金预时效后硬度提高约28%,加入稀土后较为适宜的预时效工艺为140℃10 min。
By adding different content rare element, the effect of Re on the aging characteristics and mechanical properties of Al- Mg-Si auto sheets was investigated. The results show that the aging temperature and time have great effect on mechanical properties. Increasing aging temperature can short peak aging time, but the hardness is lower. The RE can refine the precipitates on grain botmdary, improve the shape and distribution of precipitate in matrix. And the size of precipitates in matrix is also decreased. Therefore, the aging process is accelerated and the hardness value of sheets is improved. Pre-aging increases the density and volume of precipitates after artificial aging, which decreases the disadvantage of the nature aging and improves the hardness of auto sheets. The hardness of auto sheets containing RE is improved by 43% - 81% compared with that of the auto sheets that is not pre-aged. The suitable pre-aging process is 140℃ 10 min.
出处
《轻合金加工技术》
CAS
北大核心
2007年第3期49-53,共5页
Light Alloy Fabrication Technology