고압 금형 주조용 Al-9%Si-0.3%Mg합금의 Fe, Mn 함량이 인장특성 및 금형소착반응에 미치는 영향

Abstract

Effect of iron and manganese contents on the tensile properties and die soldering reaction has been studied in Al-9wt%Si-0.3wt%Mg alloy. As Fe content of Al-9wt%Si-0.3wt%Mg-0.5wt%Mn melts increased from 0.15wt% to 0.45wt%, tensile strength of each alloy was nearly same, 275 MPa but, elongation of each alloy decreased from 4.1% to 3.6%. However when Mn content of Al-9wt%Si-0.3wt%Mg -0.45wt%Fe melts increased from 0.3wt% to 0.5wt%, tensile strength of each alloy was 265 MPa and 275 MPa respectively and, elongation of each alloy increased from 2.3% to 3.6%. Ternary αhcp-Al8Fe2Si and αbcc-Al8Fe2Si intermetallic compounds formed by interaction diffusion between Al-Si-Mg system alloy melt and SKD 61 die steel surface. Thickness of soldering reaction layer in die steel surface decreased as Fe and Mn contents of the melts increased : When Fe content of Al-9wt%Si-0.3wt%Mg melts at constant 0.5wt%Mn content was 0.15wt%, 0.45wt% and 0.6wt%, thickness of soldered layer of each alloy was 64.5㎛, 57.3㎛ and 46.9㎛ respectively. For Mn content of the alloy melts at constant 0.45wt%Fe content was 0.30wt%, 0.50wt% and 0.70wt%, thickness of soldered layer of each alloy was 66.1㎛, 57.3㎛ and 48.3㎛ respectively.