Philosophical Magazine ( IF 1.6 ) Pub Date : 2021-04-17 , DOI: 10.1080/14786435.2021.1912846 Dongling Qian 1 , Tengfei Cheng 1 , Wenjie Gao 1 , Yitao Yang 1
ABSTRACT
The influences of Mn level (0–0.8 wt%) on the microstructure and mechanical properties of as-cast and T6 heat-treated low-silicon cast aluminium alloys were investigated. The results indicated that the addition of 0.5% Mn completely transformed the needle-like β-Fe phase in as-cast condition into a small-sized π-Fe phase, and the π-Fe phase was fully dissolved after T6 heat treatment. The as-cast and T6 heat-treated alloys with 0.5% Mn achieved the best combination of strength and ductility. However, an excess addition of Mn reduced the mechanical properties due to the occurrence of coarse π-Fe phase (as-cast state), α-Al(Fe, Mn)Si phase (T6 heat-treated state) and eutectic Si. With the increase of Mn content from 0 to 0.8%, the fracture modes of the as-cast alloys changed from intergranular + cleavage fracture to intergranular + quasi-cleavage fracture; The fracture modes of the T6 heat-treated alloys underwent a transition from intergranular + cleavage fracture to quasi-cleavage fracture and then to intergranular + cleavage fracture.
中文翻译:
不同Mn含量低硅铸铝合金的组织演变及力学性能
摘要
研究了 Mn 含量 (0-0.8 wt%) 对铸态和 T6 热处理低硅铸造铝合金的显微组织和机械性能的影响。结果表明,0.5% Mn的加入使铸态的针状β-Fe相完全转变为小尺寸的π-Fe相,经T6热处理后π-Fe相完全溶解。含 0.5% Mn 的铸态和 T6 热处理合金实现了强度和延展性的最佳组合。然而,由于粗的 π-Fe 相(铸态)、α-Al(Fe,Mn)Si 相(T6 热处理状态)和共晶 Si 的出现,过量添加 Mn 降低了机械性能。随着Mn含量从0增加到0.8%,铸态合金的断裂方式从晶间 + 解理断裂至晶间 + 准解理断裂;T6热处理合金的断裂方式经历了从晶间 + 解理断裂到准解理断裂再到晶间+ 解理断裂的转变 。