CAJ | 학술논문

对AZ91镁合金铸板进行搅拌摩擦加工，研究热处理对被加工材料组织和力学性能的影响。结果表明，经413℃保温16 h固溶处理后，铸态合金晶界处粗大的网状β-Mg 17 Al 12相基本溶入α-Mg基体中。在搅拌摩擦加工过程中，组织发生明显细化，产生细小的等轴状再结晶晶粒。预先固溶处理可使摩擦加工合金晶界处少量未溶β-Mg 17 Al 12相全部溶入基体。随后时效处理导致β-Mg 17 Al 12相以两种方式析出，时效初期以晶界处非连续析出为主，然后再发生晶粒内部的连续析出。时效处理可较大程度地提高合金的硬度，以16 h最为显著，搅拌区平均显微硬度的最大值为118.4HV。预先固溶处理可以提高搅拌摩擦加工合金的塑性，伸长率为31.5%；随后时效处理(16 h)则可以大幅度提高合金的抗拉强度，由搅拌摩擦加工板的265 MPa增至340 MPa。
대AZ91미합금주판진행교반마찰가공，연구열처리대피가공재료조직화역학성능적영향。결과표명，경413℃보온16 h고용처리후，주태합금정계처조대적망상β-Mg 17 Al 12상기본용입α-Mg기체중。재교반마찰가공과정중，조직발생명현세화，산생세소적등축상재결정정립。예선고용처리가사마찰가공합금정계처소량미용β-Mg 17 Al 12상전부용입기체。수후시효처리도치β-Mg 17 Al 12상이량충방식석출，시효초기이정계처비련속석출위주，연후재발생정립내부적련속석출。시효처리가교대정도지제고합금적경도，이16 h최위현저，교반구평균현미경도적최대치위118.4HV。예선고용처리가이제고교반마찰가공합금적소성，신장솔위31.5%；수후시효처리(16 h)칙가이대폭도제고합금적항랍강도，유교반마찰가공판적265 MPa증지340 MPa。
AZ91 magnesium alloy sheet was subjected to friction stir processing (FSP), and the microstructure and mechanical properties of the experimental materials were investigated. The results show that coarseβ-Mg 17 Al 12 networks dissolve into the α-Mg matrix after solution treatment (ST) at 413 ℃ for 16 h. FSP results in the significant grain refinement and the generation of equiaxed recrystallized grains. Only a few β-Mg 17 Al 12 phases are found at the grain boundaries in the FSP specimen, while these phases disappear in the pre-ST+FSP specimen. Two types of precipitates, i.e. discontinuous precipitation (DP) and continuous precipitation (CP), are found after aging treatment. The lamellar DPs are the dominant ones at the initial aging, and the CPs form within the grains. Aging treatment can improve the microhardness, with the maximum average value of 118.4HV (16 h). The pre-ST+FSP specimen shows excellent ductility with an elongation of 31.5%. Succedent aging treatment can remarkably improve the tensile strength of the alloy, which increases from 265 MPa in the FSP alloy to 340 MPa.