多向强应变和时效处理对Al-Zn-Mg-Cu合金摩擦磨损性能的影响

Influence of multi-directional strong strain and aging treatment on frictional wear properties for Al-Zn-Mg-Cu alloy

为探明多向强应变和时效处理对Al-Zn-Mg-Cu合金的显微组织、力学性能和摩擦磨损性能的影响,以多向锻造和时效处理工艺加工Al-Zn-Mg-Cu合金,对其显微组织进行了表征,并对其力学性能和摩擦磨损性能进行了测试。研究结果表明:经多向锻造加工后,Al-Zn-Mg-Cu合金的强度和硬度提高,但伸长率和耐磨性却大幅度下降。锻造合金再经120℃×1320 min时效处理后,强度和硬度进一步提高,伸长率得到明显改善,耐磨性增强。Al-Zn-Mg-Cu合金的抗拉强度、硬度和伸长率分别达到644 MPa、210 HV和14.9%,耐磨性较挤压T6态提高了68.3%。由于高的硬度和加工硬化使耐磨性增强,并且晶界析出相的不连续分布降低了晶界处的应力集中,从而也改善了Al-Zn-Mg-Cu合金的耐磨性。

In order to explore the influences of multi-directional strong strain and aging treatment on microstructure, mechanical properties and friction and wear properties of Al-Zn-Mg-Cu alloy, Al-Zn-Mg-Cu alloy was processed by multi-directional forging and aging process, its microstructure was characterized, and its mechanical properties and friction and wear properties were tested. The results shows that the strength and hardness of Al-Zn-Mg-Cu alloy are increased by multi-directional forging, but its elongation and wear resistance are substantially decreased. After aging treatment for the forged alloy at 120 ℃ for 1320 min, the strength and hardness of Al-Zn-Mg-Cu alloy are further increased, the elongation is significantly improved, and the wear resistance is enhanced. The tensile strength, hardness and elongation of Al-Zn-Mg-Cu are 644 MPa, 210 HV and 14.9%, respectively. The wear resistance is improved by 68.3% compared with the extruded T6 state due to the high hardness and high work hardening. Furthermore, due to the discontinuous distribution of grain boundary precipitates, the stress concentration at grain boundary is reduced, and the wear resistance of Al-Zn-Mg-Cu alloy is also improved.