基体合金时效行为的影响
(1.四川大学 制造科学与工程学院，成都 610065；
2.四川大学 金属材料工程系，成都 610065)
摘 要: 用挤压铸造方法制备了Mullite/Al-Cu-Si复合材料。用硬度(HB)测试仪、差示扫描量热仪(DSC)和显微镜研究含Si量变化和Mullite纤维对Al-Cu-Si合金时效硬化行为的影响；元素Si、Mullite纤维以及二者同时存在对Al-Cu-Si合金时效析出序列的影响。结果表明：Si和Mullite纤维明显抑制了Al-Cu合金GP区的形成；随着含Si量增加，Al-Cu-Si合金的时效硬化过程加快；Mullite纤维对Al-Cu和Al-Cu-Si合金的时效硬化过程都具有加速作用，同时提高了基体合金的时效硬度，但相对而言，Mullite纤维对无Si的Al-Cu合金的时效硬化加速作用更为明显一些。
关键字: Mullite纤维；Si；Al-Cu-Si合金；时效硬化
behaviours of Mullite/Al-Cu-Si
composite and its base alloy
（1.School of Manufacturing Science and Engineering，
Sichuan University,Chengdu 610065，China；
2.Department of Metallic Materials Engineering，
Sichuan University，Chengdu 610065，China）
Abstract:Short Mullite fibre reinforced Al-4.0Cu-Si composites and their monolithic alloys with different Si content (0%，2%，5%，7%) we re fabri cated by squeeze casting.The effects of Si content and short Mullite fibre on the age-hardening behaviours of composites and the effects of Si，Mullite fibre and both of them on the precipitation procedure have be en investigated by means of hardness(HB) measurement device，differential scanning calorimeter (DSC) and optical micrograph.It is shown that GP zone formation is heavily suppressed by either Si or Mullite fibre. With the increasing of Si content，the age-hardening response of Al-Cu-Si ternary alloys is accelerated.The acceleration of ageing is observed both in Mullite fibre reinforced Al-Cu composite and in mullite fibre reinforced Al-Cu-Si composite and the aged hardness of the testing composites is largely increased.Relatively speaking，the acceleration effect of mullite fibre in silicon free (no addition of silicon) AlCu based compos ite is greater than that in silicon containing Al-Cu-Si based composites.
Key words: Mullite fibre; Si; Al-Cu-Si alloy; ageing
