【作者】 逄锦程；

【导师】 乔英杰； 耿林；

【作者基本信息】 哈尔滨工程大学 ， 材料学， 2009， 硕士

【摘要】 本文采用机械合金化(MA)与真空热压烧结(HP)的方法制备了Al-Pb合金,并进行了热挤压变形处理。采用XRD、SEM、TEM研究Al-Pb合金的微观组织,研究了其热压缩变形行为,对其室温拉伸性能、阻尼性能进行了测试,并计算了其辐射防护性能。通过SEM和XRD对由MA制备的Al-Pb合金进行研究。结果表明,在MA过程中,Al与Pb并不发生反应。随着MA过程中球磨时间的增加,Pb的尺寸不断减小,一段时间后趋于稳定。这是由于在MA过程中,合金在钢球球磨作用下,产生形变、冷焊与破碎三种效应所致。同时,Al-Pb合金晶粒尺寸随球磨时间的增加而不断减小,一段时间后趋于稳定。通过XRD对真空热压烧结与热挤压后的合金试样进行物相分析,发现Al、Pb之间同样没有发生反应。用SEM对Al-Pb合金形貌进行观察,发现由于烧结时Pb原子的扩散使得Pb粒子长大。热挤压能够有效细化Al基体上的Pb粒子,是因为在进行挤压时液相Pb受到周围Al基体的作用产生破碎。本文还测试了Al-Pb合金的室温力学性能。由于合金本身的细晶强化作用,同时,弥散分布的Pb又起到了弥散强化的作用,使得Al-Pb合金力学性能远大于纯Al,使其能够应用于实际应用领域。对Al-Pb合金的辐射防护性进行了理论计算。通过阻尼温度谱测试了Al-Pb合金的阻尼性能,分析了阻尼峰的产生机理,发现两个阻尼峰分别来自晶界处的滑移与Pb相的熔化。分析了Al-Pb合金的高温变形行为,研究了峰值应力下降的原因,计算了表观激活能并建立流变应力方程,结果表明其高温变形行为受热激活控制。更多还原

【Abstract】 The Al-Pb alloy was fabricated by mechanical alloying and vacuum hot-pressed sintering and hot extrusion. The microstructure of alloy was analysed by XRD and TEM. The tensile properties at room temperature, and damping propertie were measured. Hot compression property was studied. Radiation protection property was measured.The process of mechanical alloying of Al-Pballoy was investigated alloy by SEM and XRD.The restults showed that no reactin occurred between Al and Pb. With the milling time increasing in mechanical alloying process, Pb particles size decreased and finally tended to be stable. In the process of alloying, Al-Pb alloy was impacted by steel balls.The deformation, cold welding and fragmentation affect alloying. At the same time, the grain size of the alloy also decreased with milling time increasing, and was tended to be stable after a period of time.The alloy repareing vacuum hot pressing and hot extrusion was investigated by XRD. There was also no new phase. Al-Pb alloy was observed by SEM. Hot extrusion could effectively refine the Pb particles, because liquid phase Pb was affect by Al matrix during the extrusion, and was broken into more small particles.The tensile properties at room temperature were measured. Because of the role of the fine-grain strength and dispersion strength which is due to the distribution of Pb particles, Al-Pb alloy mechanical property is better than pure Al. Radiation protection was calculated. Through the damping temperature spectrum test, Al-Pb alloy damping performance was studied. Its damping peaks come from the grain boundary sliding and liquid phase Pb, respectively.The hot deformation behavior of Al-Pb alloys was analyzed. The apparent activation energy was calculated. The flow stress equation was established, and the thermal deformation process is controlled by heat activation.更多还原