冷热循环处理对Fe基块体非晶合金摩擦磨损性能的影响

本文中采用电弧熔炼和感应熔炼后喷铸的方法制备了厚度为4 mm的Fe基块体非晶合金. 通过对Fe41Co7Cr15Mo14C15B6Y2块体非晶合金进行30次和60次冷热循环处理，并在往复式摩擦磨损条件下，研究冷热循环工艺对其摩擦磨损性能的影响. 结果表明：冷热循环处理没有显著改变铁基非晶合金的非晶态结构. 30次冷热循环处理后，Fe基块体非晶合金发生了明显的软化，平均硬度由铸态的16.06 GPa降为14.06 GPa，平均弹性模量由241 GPa降为216 GPa. 随着冷热循环次数和载荷的增加，非晶合金的平均摩擦系数和磨损率先减小后增大. 冷热循环处理有利于降低非晶合金的平均摩擦系数和磨损量. 当冷热循环次数为30次、载荷为30 N时，铁基非晶的摩擦系数由0.77降至0.72，表现出最小的摩擦系数，同时磨损率降低13.3%，表现出最小的磨损率[1.04×10−6 mm3/(m·N)]. 铸态Fe基块体非晶合金的磨损机理以疲劳断裂为主，伴随着轻微的磨粒磨损. 随着冷热循环次数的增加，疲劳导致的脆性断裂程度降低，磨损机制向磨粒磨损和疲劳断裂的共同作用转变. 所以，冷热循环处理有望成为调控非晶态金属材料摩擦学性能的有效手段. 进一步深化对冷热循环处理的理解，必将有利于推动非晶态材料在摩擦学领域的应用.

In this study, Fe-based bulk metallic glass (BMG) alloys with a thickness of 4 mm were prepared through arc melting followed by induction melting and jet casting. The Fe41Co7Cr15Mo14C15B6Y2 bulk metallic glass alloy was subjected to 30 and 60 thermal cycling treatments, and the effect of the thermal cycling process on its friction and wear properties was investigated under reciprocating friction and wear conditions. The results demonstrate that thermal cycling treatment does not significantly alter the amorphous structure of the Fe-based bulk metallic glass alloy. After 30 thermal cycles, the Fe-based BMG undergoes obvious softening, with its average hardness decreasing from 16.06 GPa in the as-cast state to 14.06 GPa, and its average elastic modulus decreasing from 241 GPa to 216 GPa. As the number of thermal cycles and applied load increase, the average friction coefficient and wear rate of the BMG first decrease and then increase. Thermal cycling treatment helps to reduce the average friction coefficient and wear loss of the BMG. When the number of thermal cycles is 30 and the applied load is 30 N, the friction coefficient of the Fe-based BMG decreases from 0.77 to 0.72, showing the minimum friction coefficient, while the wear rate is reduced by 13.3% to 1.04×10−6 mm3/(m·N), exhibiting the minimum wear rate. The wear mechanism of the as-cast Fe-based bulk metallic glass alloy is mainly fatigue fracture, accompanied by slight abrasive wear. With the increase in the number of thermal cycles, the degree of brittle fracture caused by fatigue decreases, and the wear mechanism transitions to the combined action of abrasive wear and fatigue fracture. Therefore, thermal cycling treatment is expected to become an effective method to regulate the tribological properties of amorphous metallic materials. Further deepening the understanding of thermal cycling treatment will contribute to promoting the application of amorphous materials in the field of tribology.