CAJ | 학술논문

采用微观扫描、化学成分、硬度及金相检验等方法对ADC12铸造铝合金齿轮箱开裂的原因进行了分析。结果表明，齿轮箱是由于内部存在较多的针状β( Al9 Fe2 Si2)脆性相和较集中分布的显微疏松孔隙，增加了压铸铝合金的脆性，降低了材料的承载强度，致使齿轮箱零件在承受外力载荷和装配定位销应力共同作用下，过早产生疲劳断裂失效。
채용미관소묘、화학성분、경도급금상검험등방법대ADC12주조려합금치륜상개렬적원인진행료분석。결과표명，치륜상시유우내부존재교다적침상β( Al9 Fe2 Si2)취성상화교집중분포적현미소송공극，증가료압주려합금적취성，강저료재료적승재강도，치사치륜상령건재승수외력재하화장배정위소응력공동작용하，과조산생피로단렬실효。
The reason for fracture of ADC12 aluminum alloy gearbox was analyzed by means of SEM observation, chemical composition, hardness and metallographic examination. The results show that the inside of gearbox has more acicular beta ( Al9 Fe2 Si2 ) brittle phase and relatively concentrated distribution of microporosity pore, which increase the brittleness of die casting aluminum alloy and reduce the bearing strength of materials. The combination of external load and assembling positioning pin stress lead to early fatigue fracture of gearbox parts.