WSP流变铸造与球化处理对Al-18%Si-5%Fe合金组织和性能的影响

Effects of wavelike sloping plate rheocasting and spheroidisation on microstructures and properties of Al-18%Si-5%Fe alloy

提出了波浪形倾斜板流变铸造(WSP)装置制备过共晶Al-Si-Fe合金的方法,对Al-18%Si-5%Fe合金流变铸造与球化处理进行研究。结果表明,WSP流变铸造可以明显改善合金中初晶硅、Al18Si10Fe5和Al8Si2Fe相的形貌。随着浇注温度降低,各相趋于细化和球化。WSP流变铸造过程中合金组织的形成源于3种机制:结晶雨带来的晶核增殖,斜板强冷却作用下晶体抑制生长和流动剪切作用下晶体破碎。WSP流变铸造与球化处理进一步改善Al-18%Si-5%Fe合金组织,合金维氏硬度达到87.5。在干摩擦条件下Al-18%Si-5%Fe合金的磨损率达到5.4 mg/h。

A novel method of preparing hypereutectic Al-Si-Fe alloy was proposed by wavelike sloping plate（WSP） rheocasting device,and the rheocasting and spheroidisation treatment of Al-18%Si-5%Fe alloy were investigated.The results reveal that the morphologies of primary crystal Si,Al18Si10Fe5 and Al8Si2Fe phase in this alloy can be improved obviously by WSP rheocasting.With the decrease of pouring temperature,various phases tend to be refined and spheroidised.The formation of microstructures in this alloy originates from three mechanisms such as crystal nucleus multiplication brought by crystallization rain,crystal restraining growth under strong cooling of sloping plate and crystal break-up under flow shear.The WSP rheocasting and spheroidisation treatment further improve the microstructure of Al-18%Si-5%Fe alloy.The Vickers hardness of the alloy is 87.5.The wear rate of Al-18%Si-5%Fe alloy under dry friction is 5.4 mg/h.