Narain Vikas, Ray Subrata
Shri Bhawani Niketan Institute of Technology and Management, India.
Indian Institute of Technology Mandi, India.
Heliyon. 2020 Jan 27;6(1):e03275. doi: 10.1016/j.heliyon.2020.e03275. eCollection 2020 Jan.
The Al-Mg-MnO composite is a MnO particulate reinforced Al metal matrix composite. Its substantial ductility makes it promising composite for study. The Al-3Mg-MnO and Al-8Mg-MnO composites were synthesized by stirring 3, 5, and 8 wt% of MnO particulates in Al-3Mg melt and Al-8Mg melt to study their mechanical properties. Their microstructure shows intermetallic precipitates of Al, Mg, and Mn at dendrites, grain boundaries and within the grains. In both sets of composites, the hardness, and the yield strength increases with increasing MnO content in the cast and forged composites. Both the groups of composites show an increase in tensile strength with increasing particle content from 3 to 5 wt%, a further increase in particle content to 8 wt%, leads to an abrupt decrease in tensile strength in both the group of composites. The percentage elongations in forged composites are lower than those in cast composites, but this decrease is more prominent in Al-8Mg-MnO composites in comparison to Al-3Mg-MnO composites. The value decreases as the percentage of MnO particles increases in Al-3Mg-MnO and Al-8Mg-MnO composites. Forging increases values in both the class of composites in comparison to their cast counterparts due to work hardening and healing of pores. Crack growth toughness also decreases as the MnO particle content increases in Al-3Mg-MnO and Al-8Mg-MnO composites. Forged Al-3Mg-MnO shows decreased T/E ratio in comparison to their cast counterparts except at 8wt%. However, forged Al-8Mg-MnO shows improved T/E at 3wt% and a drop at 5wt% and 8wt% MnO. Variation of crack growth toughness between cast and forged Al-8Mg-MnO is minimal in comparison to that between cast and forged Al-3Mg-MnO composites.
铝镁-二氧化锰复合材料是一种二氧化锰颗粒增强铝基金属基复合材料。其良好的延展性使其成为很有研究前景的复合材料。通过在铝-3镁熔体和铝-8镁熔体中搅拌3%、5%和8%重量比的二氧化锰颗粒来合成铝-3镁-二氧化锰和铝-8镁-二氧化锰复合材料，以研究它们的力学性能。其微观结构显示在枝晶、晶界和晶粒内部存在铝、镁和锰的金属间析出物。在这两组复合材料中，铸造和锻造复合材料的硬度以及屈服强度都随着二氧化锰含量的增加而提高。两组复合材料的抗拉强度都随着颗粒含量从3%增加到5%而提高，颗粒含量进一步增加到8%时，两组复合材料的抗拉强度都会突然下降。锻造复合材料的伸长率百分比低于铸造复合材料，但与铝-3镁-二氧化锰复合材料相比，这种下降在铝-8镁-二氧化锰复合材料中更为明显。在铝-3镁-二氧化锰和铝-8镁-二氧化锰复合材料中，随着二氧化锰颗粒百分比的增加， 值会降低。由于加工硬化和孔隙愈合，与铸造的同类复合材料相比，锻造使这两类复合材料的 值都有所提高。在铝-3镁-二氧化锰和铝-8镁-二氧化锰复合材料中，随着二氧化锰颗粒含量的增加，裂纹扩展韧性也会降低。除了在8%重量比时，锻造的铝-3镁-二氧化锰与铸造的同类复合材料相比，其T/E比有所降低。然而，锻造的铝-8镁-二氧化锰在3%重量比时T/E有所提高，在5%和8%重量比的二氧化锰时则下降。与铸造和锻造的铝-3镁-二氧化锰复合材料之间相比，铸造和锻造的铝-8镁-二氧化锰之间裂纹扩展韧性的变化最小。
