摘要
采用DSC以及光学显微镜与扫描电镜研究了富Ce稀土(0.1wt%,0.3wt%,0.5wt%)对多元近共晶Al-11.5Si-4Cu-2Ni-1Mg-0.5Fe(wt%)活塞合金凝固组织的影响。发现富Ce稀土加入对该合金的共晶硅和多种第二相的凝固温度、形态与体积分数均有明显影响。富Ce稀土的加入,使Al-Si共晶温度降低,T-Al_(9)FeNi相和δ-Al_(3)CuNi相析出温度升高。富Ce稀土加入量0.3wt%时,共晶硅变质效果最佳,T-Al_(9)FeNi相由初始的板条状转变为小块状,体积分数减小到3.22vol%,δ-Al_(3)CuNi相由初始的片状转化为鱼骨状,体积分数增加到6.47vol%。富Ce稀土中La、Ce原子在凝固过程中富集在固液界面前沿,增大了成分过冷,细化共晶组织。当富Ce稀土含量为0.5wt%时,合金中出现长针状富稀土相。
The effect of Ce-rich rare earth(0.1wt%,0.3wt%,0.5wt%)on the solidification microstructure of multivariate near-eutectic Al-11.5Si-4Cu-2Ni-1Mg-0.5Fe(wt%)piston alloy was studied by DSC,optical microscopy and scanning electron microscopy.It is found that the addition of Ce-rich rare earth has obvious effects on the solidification temperature,morphology and volume fraction of eutectic silicon and various second phases of the alloy.The addition of Ce-rich rare earth reduces the Al-Si eutectic temperature and increases the precipitation temperature of T-Al_(9)FeNi phase and δ-Al_(3)CuNi phase.When the addition of Ce-rich rare earth is 0.3wt%,the modification effect of eutectic silicon is best,T-Al_(9)FeNi phase changes from the initial lath shape to the small block shape,the volume fraction decreases to 3.22vol%,and the δ-Al_(3)CuNi phase changes from the initial flake shape to fishbone shape,the volume fraction increases to 6.47vol%.La and Ce atoms in the Ce-rich rare earth are enriched at the front of the solid-liquid interface during the solidification process,which increases the compositional supercooling and refines the eutectic structure.When the content of Ce-rich rare earth is 0.5wt%,long needle-like rare earth-rich phase appears in the alloy.
作者
刘铁羽
董雄博
段洪波
夏峰
杨伟
王建利
李建平
LIU Tieyu;DONG Xiongbo;DUAN Hongbo;XIA Feng;YANG Wei;WANG Jianli;LI Jianping(Engineering Research Centre of Light Alloys and Composites of Shaanxi Province,School of Materials and Chemical Engineering,Xi'an Technological University,Xi'an 710021,China)
出处
《热加工工艺》
北大核心
2024年第9期95-100,共6页
Hot Working Technology
基金
陕西省重点研发计划项目(2020ZDLGY13-01)
西安市智能兵器重点实验室项目(2019220514,SYS020CG 042)。
关键词
铝-硅活塞合金
变质
共晶硅
富铈稀土
Al-Si piston alloy
modification
eutectic silicon
Ce-rich rare earth
