铸造2026，Vol.75Issue(8)：877-884,8.DOI:10.27014/j.cnki.zhuzao.2026.0113
机械切屑诱发的局部冷铁效应与富铁相选择性析出机理
Mechanisms of Local Chill Effect Induced by Cutting Chips and Selective Precipitation of Fe-Rich Phases
摘要
Abstract
Taking the Al-12Si-Fe alloy as the matrix and charging the cutting chips with different mass fractions(0-3%)to establish a coupled effect field of local chilling-heterogeneous nucleation,the influence of it on solidification microstructure and mechanical properties was systematically investigated.The results show that with insufficient chip feed(≤1.5%),only local chilling and solute segregation occur,leading to coarsening of eutectic/primary Si.With an appropriate amount(2.5%),oxide films and impurity clusters on the chip surfaces serve as potential nucleation substrates,significantly increasing nucleation density and promoting equiaxed grain formation,suppressing large-scale segregation of Fe-rich phases,thereby improving microstructural homogeneity and toughness.Whereas excessive charging chips(3.0%)act as crack initiation sites due to poor interfacial wetting and fusion.When the chip addition is 2.5%,the tensile strength of the alloy is increased from approximately 181 MPa to 213 MPa and the elongation is increased from approximately 4.5%to 6.4%.Furthermore,based on critical nucleation work,secondary dendrite arm spacing,and columnar-to-equiaxed transition(CET)conditions,a quantitative relationship between"chip addition-effective undercooling-equiaxed grain density"was established and an optimal process parameter window was proposed,providing a new approach for precise microstructure/property control and high-value utilization of recycled Al-Si-Fe alloys.关键词
机械切屑/冷铁效应/富铁相/柱-等轴转变(CET)/异质形核Key words
cutting chip/chill effect/Fe-rich phase/columnar-to-equiaxed transition(CET)/heterogeneous nucleation分类
矿业与冶金引用本文复制引用
覃皓,李越,唐鹏..机械切屑诱发的局部冷铁效应与富铁相选择性析出机理[J].铸造,2026,75(8):877-884,8.基金项目
国家自然科学基金(52261024) （52261024）
广西自然科学基金(2025GXNSFAA069657,2023GXNSFAA026374). （2025GXNSFAA069657,2023GXNSFAA026374）
