论文部分内容阅读
研究了不同变质剂对过共晶铝硅合金微观组织和性能的影响。结果表明:经过不同变质剂变质后,初晶硅更加细小、均匀地分布于基体中,其中Al-Cu-P变质剂变质效果最好,其初晶硅尺寸细化到25μm左右,硬度和强度均提高了20%以上。探讨了固溶和时效处理对合金微观组织的影响,经过T6处理后,析出的强化第二相均匀弥散地分布于基体中,其中经Al-Cu-P变质的合金经T6处理后,其硬度达到153HV,常温抗拉强度达到250MPa。对拉伸试样断口进行分析,发现其变质前后断裂均为脆性断裂,主要是沿晶断裂和穿晶解理断裂的交互进行。
The effects of different modifiers on microstructure and properties of hypereutectic Al-Si alloys were investigated. The results show that the primary silicon is more finely and uniformly distributed in the matrix after being modified by different modifiers. The Al-Cu-P modifier has the best metamorphic effect. The primary Si size is refined to about 25μm. The hardness and strength Have increased by more than 20%. The effects of solution treatment and aging treatment on the microstructure of the alloy were investigated. After T6 treatment, the precipitated reinforcing second phase was uniformly and dispersively distributed in the matrix, and the hardness of the Al-Cu-P modified alloy after T6 treatment Reached 153HV, room temperature tensile strength reached 250MPa. The fracture of the tensile specimen was analyzed and it was found that the faults were brittle fracture before and after the metamorphism, which was mainly caused by the interaction between intergranular fracture and transgranular cleavage fracture.