CAJ | 학술논문

研究了不同含量Ce/La(x=0,0.1,0.5,1.0)对AZ91D镁合金显微组织及蠕变性能的影响.通过X射线衍射(XRD)、金相显微镜(OM)、扫描电镜(SEM)及能谱分析(EDX)观察与分析表明,压铸AZ91D镁合金中添加Ce/La后,除了α-Mg,β-Mg_(17)Al_(12)相之外,还生成了新的稀土化合物Al_(11)RE_3(RE=Ce/La)化合物,并且细化了合金显微组织、提高了合金室温和高温力学性能.生成的Al_(11)RE_3(RE:Ce/La)高温热稳定相使AZ91D+xCe/La(x=0,0.1,0.5,1.0)合金在150℃,50MPa下的蠕变抗力优于AZ91D镁合金,1%Ce/La的合金与AZ91D相比,蠕变延伸率低了0.2%,最小蠕变速率从2.30×10~(-8)s~(-1)降低到2.02×10~(-8)s~(-1).蠕变试样的微观组织结构分析表明:AZ91D合金的蠕变机制主要以晶界滑移方式为主,Al_(11)RE_3(RE=Ce/La)热稳定相在晶界处延缓和阻碍了晶界断裂的过程.
연구료불동함량Ce/La(x=0,0.1,0.5,1.0)대AZ91D미합금현미조직급연변성능적영향.통과X사선연사(XRD)、금상현미경(OM)、소묘전경(SEM)급능보분석(EDX)관찰여분석표명,압주AZ91D미합금중첨가Ce/La후,제료α-Mg,β-Mg_(17)Al_(12)상지외,환생성료신적희토화합물Al_(11)RE_3(RE=Ce/La)화합물,병차세화료합금현미조직、제고료합금실온화고온역학성능.생성적Al_(11)RE_3(RE:Ce/La)고온열은정상사AZ91D+xCe/La(x=0,0.1,0.5,1.0)합금재150℃,50MPa하적연변항력우우AZ91D미합금,1%Ce/La적합금여AZ91D상비,연변연신솔저료0.2%,최소연변속솔종2.30×10~(-8)s~(-1)강저도2.02×10~(-8)s~(-1).연변시양적미관조직결구분석표명:AZ91D합금적연변궤제주요이정계활이방식위주,Al_(11)RE_3(RE=Ce/La)열은정상재정계처연완화조애료정계단렬적과정.
The effect of Ce/La on the microstructures and creep property of die-cast AZ91D alloys containing varied contents of Ce/ La (0%, 0. 1%, 0.5%, 1.0% ) was studied. X-ray diffraction, optical microscopy, scanning electron microscopy and energy dis-perse spectroscopy were used to analyze microstructures and creep properties of the alloys at room temperature and high temperature. Results showed that the new phase compositions of die-cast AZ91D alloys adding in a small amount of Ce/La mainly consisted of β-Mg_(17)Al_(12) and Al_(11) RE_3 ( RE = Ce/La) phases. It not only refined the microstructure and improved mechanical properties of alloy but al-so improved the creep resistant properties of alloy. Compared 1% Ce/La with AZ91D, the total strain of alloy decreased 0.2% and the minimum creep rate decreased from 2.30 × 10~(-8)s~(-1) to 2.02 × 10~(-8) s~(-1). The creep resistant of the alloy with the heat-resistant phases was superior to that of AZ91D alloy. The results indicated that the creep mechanism of AZ91D alloy was the grain boundary sliding and the heat-resistant phases postponed the process of creep resistant and improved the creep resistant properties of AZ91D alloy.