SiC颗粒增强Al-13Si-Cu-Mg基复合材料制备与持久性能研究

发布时间：2018-05-14 06:52

  本文选题：搅拌铸造 + SiCp/Al复合材料　； 参考：《西安工业大学》2015年硕士论文

【摘要】：SiC颗粒增强铝基复合材料具有高比强度,高刚度,耐疲劳,耐磨损,热膨胀系数低,优良的尺寸稳定性,较强的可设计性等优点,在汽车工业、航空航天、电子、军工、体育等许多领域得到广泛的应用。国内外对于SiC颗粒增强铝基复合材料展开了大量研究,取得了一些重要应用成果,但是材料性能方面无法满足大功率柴油机活塞的使用要求,并且制备工艺方面仍然达不到大规模的工业生产需要。为了提高铝活塞合金综合力学性能,以满足高功率柴油发动机对活塞材料的要求。本文设计将10μmSiC颗粒加入到Al-13Si-Cu-Mg合金中,通过粉末冶金法与搅拌铸造法相结合制备SiC颗粒增强铝基复合材料,解决了微小增强体SiC颗粒难以加入到铝合金中的问题,通过高剪切搅拌解决SiC颗粒在铝合金中的分布不均匀问题,并运用SEM、TEM对制备的复合材料进行SiC颗粒/A1界面分析。为了分析活塞合金在高温高压条件下组织性能的变化,建立铝合金微观组织与宏观性能关系模型。本文重点对活塞合金在350℃进行持久试验,分析性能变化规律,并采用OM、SEM、TEM分析活塞合金组织演变规律。SiC颗粒增强铝基复合材料制备中,首先采用粉末冶金法制备含SiC颗粒预制块,然后采用高剪切搅拌法,将SiC颗粒以预制块方式加入铝合金溶液中,调整搅拌温度、时间、SiC颗粒含量,确定在转速6000r/min条件下2%SiCP,700℃下搅拌5min, SiC颗粒在基体中分布均匀。并通过SEM、TEM、HRTEM进行界面分析,表明SiC颗粒增强Al-13Si-Cu-Mg基复合材料界面类型分为非晶层界面和干净界面,其中非晶层界面占大多数,且非晶层界面与界面上镁元素的富集和杂质相的形成有关。活塞合金350℃持久试验结果表明,当外加载荷为90MPa时试样直接断裂,随着外加载荷的恒定减小,持久寿命增长,当外加载荷降到30MPa时持久寿命延长至102h。通过TEM分析可知持久拉伸过程中富铜相θ"-θ'-θ的转变,和θ"相溶解是致使试样持久寿命增加合金力学性能降低的主要原因。
[Abstract]:SiC particle reinforced aluminum matrix composites have the advantages of high specific strength, high stiffness, fatigue resistance, wear resistance, low thermal expansion coefficient, excellent dimensional stability, strong designability, etc., in automotive industry, aerospace, electronics, military industry, etc. Sports and many other fields are widely used. A great deal of research on SiC particle reinforced aluminum matrix composites has been carried out at home and abroad, and some important application results have been obtained, but the material properties can not meet the requirements of the piston of high power diesel engine. And the preparation process is still not able to meet the needs of large-scale industrial production. In order to improve the comprehensive mechanical properties of aluminum piston alloy to meet the requirements of high power diesel engine piston materials. In this paper, 10 渭 mSiC particles were added to Al-13Si-Cu-Mg alloy, and SiC particle reinforced aluminum matrix composites were prepared by powder metallurgy and agitation casting, which solved the problem that SiC particles were difficult to be added to aluminum alloy. The uneven distribution of SiC particles in aluminum alloy was solved by high shear stirring, and the interfacial analysis of SiC particles / A1 was carried out by means of SEM-TEM. In order to analyze the change of microstructure and properties of piston alloy under high temperature and high pressure, the relationship between microstructure and macroscopic properties of aluminum alloy was established. In this paper, the rupture test of piston alloy at 350 鈩，

本文编号：1886792