摘要
采用原位合成方法制备了TiB2超细颗粒增强ZL109复合材料,对材料进行了高温拉伸蠕变实验。实验结果表明,复合材料在高温恒应力条件下,表现出高的名义应力指数和高的名义蠕变激活能,优于纯Al和ZL109合金,而且比常规外加颗粒复合材料具有更好的高温蠕变性能。引入门槛应力概念,复合材料的蠕变实验结果能够用微观结构不变模型来解释,说明复合材料的蠕变受到基体点阵扩散的控制。复合材料的蠕变断裂行为可以用Monkman Grant经验公式来描述,蠕变断裂特征为延性断裂。
The high temperature tensile creep tests were performed on TiB2 ultrafine paniculate reinforced ZL109 composite prepared by in situ formation technique. The composite exhibits high values of apparent stress exponent and apparent creep activation energy under constant applied stress at elevated temperatures. These values exceed greatly those for pure aluminum and ZL109 alloy. High temperature creep properties of the in situ synthesized TiB2/ZL109 composite are better than those for conventional particulate reinforced composites. By introducing a threshold stress, the creep results of the composite can be explained by a microstructure invariant model, implying that creep of the composite is controlled by lattice diffusion in the matrix. The creep rupture behavior of the composite can be represented by Monkman-Grant empirical equation and the rupture characteristic of the composite is ductile fracture.
出处
《复合材料学报》
EI
CAS
CSCD
北大核心
2005年第1期36-40,共5页
Acta Materiae Compositae Sinica
基金
国家自然科学基金项目(59901006)
关键词
TiB2/ZL109复合材料
原位合成
蠕变
颗粒
Aluminum alloys
Creep
Deformation
High temperature effects
Particles (particulate matter)
Reinforcement
Stresses
Tensile testing
Titanium compounds
