【作者】 刁晓刚；

【导师】 时海芳； 袁晓光；

【作者基本信息】 辽宁工程技术大学 ， 材料学， 2006， 硕士

【摘要】 本文以Al-Si系合金为基础,通过添加多种合金元素来提高合金的耐热、耐磨性能。采用喷射沉积快速凝固技术制备了Al-17Si-5Fe-2Ni-3.5Cu-1Mg-2Mn-1V合金。分析了合金的微观组织及形貌,测定了合金的热稳定性、拉伸性能及磨损性能。取得以下主要研究成果: 喷射沉积工艺制备的Al-Si系合金组织均匀细小,初晶Si相的形状基本是颗粒状或块状。热挤压后合金组织十分致密,初晶Si相弥散分布在基体上。T6热处理后的合金部分初晶Si相尖角有所钝化,弥散相的数量增加。挤压态合金在300℃下等温处理不同时间后,初晶Si相没有明显长大; 在不同温度等温处理12h时,直至400℃时初晶Si相尺寸才有所增大。挤压后合金室温极限抗拉强度达232.2MPa,T6处理后强度达271.3MPa。合金拉伸时裂纹起源于初晶相本身及初晶相与基体结合处。在磨损100min后,干摩擦条件下的高温磨损失重仅比常温提高了11.87%,只是A390合金失重的60.02%; 润滑条件下,100min后高温磨损累积失重量仅为A390合金失重的0.63%,常温磨损未测出失重。更多还原

【Abstract】 Multiple alloying elements are selected to improve heat-and wear-resistance of the Al-Si alloy, which is prepared by spray deposition (SD), a kind of rapid solidification (RS) technique. Its chemical composition is Al-17Si-5Fe-2Ni-3.5Cu-1Mg-2Mn-1V. Microstructure and morphologies of the alloy are investigated. Thermal stability 、 tensile properties and wear-resistance are measured. The main results are summarized as follows: Microstructure of the sprayed alloy is effectively refined. The morphology of the primary silicon phases is mainly granular or block-like. The silicon phases are dispersed in the matrix after being extruded. Volume fraction of the dispersed phases is enlarged. There is no evident phase coarsening of β-Si when as-extruded alloy is heated at 300℃ for different durations; Until 400℃, the size of primary Si phases is larger than before when heated at different temperature for 12h. Extruded alloy has a maximum tensile strength of 232.2MPa at room temperature and 271.3MPa after T6 treatment. Tensile cracks in the SD alloy generate in silicon phases or appear at interfaces boundary between the silicon phases and matrix. Study of wearing behavior reveals that weight loss of the alloy at elevated temperature is increased by 11.87% than that of the alloy at room temperature with no lubricant, and the value is 60.02% as much as A390 alloy’s. It is the same case that with the SD alloy and A390 alloy at elevated temperature with lubricant, the difference of which is that cumulative weight loss of the SD alloy is 0.63% as much as A390 alloy’s. Weight loss of the SD alloy is nearly zero at room temperature.更多还原