论文部分内容阅读
采用OM、激光导热及直读光谱等手段,研究了Sr、B变质及退火对共晶Al-Si合金组织及热导率的影响.结果表明,通过B+ Sr复合变质,共晶Si相由层片状转变为纤维状,杂质含量降低,合金的导热性能得到显著提升.B、Sr加入顺序对合金组织及导热性能有显著影响.经0.02％的B+0.03％的Sr复合变质处理合金的热导率为159.5 W/(m·K),较未变质合金提升约31.2％.经350℃×4h退火处理,B+ Sr复合变质合金的热导率为178.8 W/(m·K),较其铸态合金提升约10.93％.“,”The effects of Sr-B-modification and annealing on the microstructure and thermal conductivity of eutectic A1-Si alloy were investigated by the optical microscope,laser flash apparatus and optical emission spectrometer.The results indicate that the flake-like eutectic Si is transformed into the fibrous structure,and the A1 matrix purity is improved through B+ Sr compound modification,which obviously enhances the thermal conductivity.The addition order of Sr-B has the remarkable effects on the microstructure and thermal property.The thermal conductivity of 0.02％ B+0.03％ Sr modified alloy reaches 159.5 W/(m · K),increased by 31.2％ than that of the unmodified alloy.With the annealing treatment at 350 ℃ for 4 h,the thermal conductivity of 0.02％B+0.03％Sr modified alloy reaches 178.8 W/(m ·K),increased by 10.93％ than that of the untreated alloy.