热处理和泡沫铁对A356-SiC_(p)/Fe干滑动摩擦学性能的影响

Effect of heat treatment and foam iron on the dry slidingfrictional properties of A356-SiC_(p)/Fe

采用真空辅助熔渗工艺制备泡沫铁骨架作为增强SiC_(p)/A359复合材料A359-SiC_(p)/Fe,对比进行泡沫铁增强前后和T6热处理前后,两种材料的显微硬度和高温磨损性能,明确泡沫铁和T6热处理对A359-SiC_(p)/Fe复合材料高温磨损性能增强的效果,并结合使用SEM与EDS对表面磨损形貌、磨屑形貌的观察表征,以探究该材料在不同温度下的高温磨损机理。结果表示,使用真空辅助熔渗工艺制备A359-SiC_(p)/Fe, Al-Fe界面结合良好,不仅形成了机械结合,还形成了化学冶金结合(靠近铝基体界面的相为Al_(12)Fe_(5)Si_(3);靠近泡沫铁基体处为Fe_(2)Al_(5)相;远离泡沫铁组织,呈游离状态的合金相为Al_(4)FeSi)。A359-SiC_(p)/Fe在300~500℃的磨损量仅为未增强合金的25%~75%,有效将高温环境下的使用温度提升50~100℃以上。T6热处理能够明显提高Al基体的硬度以及Al-Fe界面的冶金结合程度,且在300~500℃时效果更明显,有效提高材料的高温耐磨性能。材料的磨削形式受温度影响,100℃时为磨粒磨损,摩擦温度到达350℃时表面出现分层和剥落,500℃时,开始粘着磨损。

Vacuum-assisted fusion infiltration process is used to prepare foam iron skeleton as the reinforcement of SiC_(p)/A359 composite material A359-SiC_(p)/Fe.The microhardness and high-temperature wear properties of the two materials before and after foam iron enhancement and T6 heat treatment were compared to make clear the effect of foam iron and T6 heat treatment on the enhancement of high-temperature wear properties of A359-SiC_(p)/Fe composite material.The use of SEM was combined with the EDS to characterize the observation of the surface wear morphology,the abrasive debris morphology,as well as wear of the longitudinal cross-section,in order to explore the high-temperature wear mechanism of the material at different temperatures.The results indicated that A359-SiC_(p)/Fe was prepared using vacuum-assisted fusion infiltration process,and the Al-Fe interface was well bonded,forming not only mechanical bonding,but also chemical metallurgical bonding.The wear amount of A359-SiC_(p)/Fe at 300-500℃was only 25%-75%of that of the unreinforced alloy,which effectively increased the use temperature in high-temperature environments by more than 50-100℃.T6 heat treatment could significantly improve the hardness of the Al matrix and the degree of metallurgical bonding at the Al-Fe interface,and the effect was more pronounced at 300-500℃,effectively improving the material's high-temperature wear resistance.The grinding form of the material was affected by the temperature,which is abrasive wear at 100℃.When the friction temperature reached 350℃,the surface appeared delamination and spalling,and adhesive wear was began at 500℃.