稀土对含硅ZA40合金高温耐磨性的影响

Effect of Rare Earth Upon Wear Resistance of ZA40 Alloy with Si at High Temperature

对含硅ZA40合金未加稀土和添加了0.05%富镧混合稀土的试样分别进行了室温及100℃、150℃干摩擦,载荷为150 N,时间为30 min条件下耐磨性试验,并观察了100℃、150℃磨损试样表面磨痕及截面形貌。结果显示稀土能显著改善含硅ZA40合金耐磨性,且与室温时相比,在高温条件下,稀土的作用更加明显。对稀土的作用分析表明:稀土的加入能有效地细化含硅ZA40合金材料的富铝α相、富铜ε相,针状共晶硅减少,块状初晶硅变得细小,因而提高了在高温条件下材料的强度,进而有效地提高了含硅ZA40合金的高温耐磨性。

The samples of ZA40 alloy containing Si with 0.05% La-rich mixed RE and without RE were respectively conducted dry wear test at room temperature, 100 ℃ and 150 ℃ high temperature with 150 N in 30 min. The traces of wear and sectional morphology were observed. The effect of Rare earths addition to ZA40 containing Si on wear resistance of high temperature was investigated in this study. The result shows that rare earth addition can effectively improve the wear resistance of materials. Compared with room temperature, effect of RE is more clearly at high temperature. It was found that rare earth addition can effectively refine the aluminum-based phase and Cu-rich phase. Besides, the amount of needle-like eutectic silicon was reduced, and massive primary silicon phase becomes small. Thus the strength of material was improved under the condition of high temperature. Thereby, wear resistance of ZA40 containing Si was effectively improved at high temperature.