【作者】 彭芳庆；

【导师】 夏天东；

【作者基本信息】 兰州理工大学 ， 材料学， 2010， 硕士

【摘要】 铝合金密度低,但强度比较高,接近或超过优质钢,塑性好,可加工成各种型材,具有优良的导电性、导热性和抗蚀性,工业上广泛使用,使用量仅次于钢。铸造铝合金因为含有足够量的共晶型Si元素,耐磨性较好,但是它的力学性能较差,使用范围大多都在制造航空器材、日常生活用品、建筑用门窗等。压力加工的变形铝合金具有良好的力学性能,在工业上很多承受件都有所应用。现在已有一些报告对于纯铝的机械变形进行研究,此外对于铝合金特别是Al-Si合金的磨损也有相当多的研究。但是,却很少有关变形铝合金的干摩擦性能研究。变形铝合金的摩擦磨损性能的研究,都是基于其表面改性工艺处理后在测定是否符合性能要求,对变形铝合金基体上的耐磨性研究甚少。本文主要针对五种变形铝合金与马氏体不锈钢和奥氏体不锈钢组成的摩擦副在温度为15℃、空气湿度为40g/m3的实验室下进行的在无润滑干摩擦状态下在M2000摩擦磨损试验机进行的干摩擦磨损性能的研究,在相同干摩擦条件下,实验在固定载荷200N的正压力、转速200r/min(0.424m/s)作用下进行2h摩擦磨损实验,每种变形铝合金在实验条件下测试五组。M2000摩擦磨损试验机得到摩擦系数和利用称重法得到体积磨损率后将数据处理分析,对他们的耐磨性进行比较,通过扫描电镜(SEM)观察其磨损表面,能谱仪分析表面微区成分,变形铝合金基体摩擦前后的微观结构、力学性能与摩擦磨损的内在联系,得到变形铝合金的摩擦磨损机理,得到以下结论：五种变形铝合金与马氏体不锈钢的平均摩擦系数在0.3～0.4之间,五种变形铝合金与奥氏体不锈钢的平均摩擦系数在0.4～0.5之间,编号A#,E#相对具有较小的摩擦系数和体积磨损率,变形铝合金在载荷作用下发生塑性变形和加工硬化,变形铝合金材料的摩擦磨损过程可以分为三个阶段。第一阶段,轻微磨损阶段；第二阶段,机械混合层形成阶段；第三阶段,机械混合层形成,剥层磨损。变形铝合金的磨损机制以粘着、磨粒磨损为主,同时伴有氧化磨损。磨粒磨损因材料性能的差异而表现出剥层磨损、块状剥落以及增强颗粒的剥落和破碎等几种磨损形式。变形铝合金在加工过程中,试样尺寸也是影响变形铝合金的一个重要因素,尺寸不同性能亦不同。管型变形铝合金与棒型铝合金高温时合金屈服强度和塑性的变化趋势大致相同,都是随着温度的提高合金屈服抗拉强度下降,温度小于等于200℃时尺寸为直径50mm的棒型变形铝合金比80mm的棒型铝合金的屈服强度和抗拉强度大。温度为250℃和300℃下不仅没有屈服现象,并且尺寸为直径50mm的棒型变形铝合金比80mm的棒型铝合金的抗拉强度小；管型变形铝合金的抗拉强度小于棒状变形铝合金的抗拉强度。更多还原

【Abstract】 Aluminum alloy has Low density、high intensity and good plasticity, excellent conductivity、thermal conductivity and resistance to corrosion, widely used in industry, usage amount rank only second to steel.Cast aluminum alloy has plenty of eutectic type Si element, good abrasion resistance, but poor mechanical properties, used mostly in scope in manufacturing aviation equipment, daily necessities, building doors and windows, etc. Press-working of deformation aluminium alloy with good mechanical properties, in industries have found application under many bear parts. Now there has been some reports for pure aluminum mechanical deformation, in addition to the Al-Si alloy, especially wear has quite a lot of research. However, seldom related dry friction properties of aluminum deformation. Research on deformation aluminium alloy tribological properties, all are based on its surface modification process in compliance with performance after the determination of aluminum matrix deformation, the research on very little resistance.This article mainly aims at five kinds of deformation aluminum alloy and martensitic stainless steel and the austenitic stainless steel composed of friction pair.In dry friction condition without lubrication friction tester M2000 in the dry friction and wear performance in 15 degrees in temperature, humidity to 40g/m3 in the laboratory. In the same dry friction condition,200N fixed load、rotate speed 200r/min (0.424m/s) experiment for friction and wear process 2 hours, each deformation aluminum alloy in experimental conditions test five times. M2000 friction and wear tester obtain Friction coefficient and the volume wear rate by weighing method,than analysis the data,compare with wear, by scanning electron microscope (SEM) to observe its wear surface, spectrometer analysis of surface composition, the internal relations for microscopic structurematrix、mechanical properties and the friction and wear of deformation aluminum friction,in order to obtain friction and wear mechanism, get the following conclusion:Five kinds of deformation of aluminum alloy and martensitic stainless steel’s average friction coefficient in between 0.3～0.4, five kinds of deformation of aluminum alloy and austenitic stainless steel’s average friction coefficient in between 0.4～0.5. The numbers of A#, E# have lower friction coefficient and volume wear rate,in the foxed load plastic deformation and processing sclerosis occurred. Deformation of aluminum alloy friction and wear process can be divided into three stages.The first stage, minor abrasion stage; The second stage, mechanically mixed layer forming stage;The third stage, mechanically mixed layer forming, peeling wear.Deformation aluminum alloy’swear mechanism to give priority to adhesive wear、abrasive wear, at the same time with oxidation wear. Abrasive wear due to the differences between material properties and show delamination wear、massive spalling and reinforced particle spalling and crushing several wear form.In the machining process, the sample size is an important factor that effects the deformation aluminum alloy, that is, the differences of properties due to the differences of the sample size. Tube type deformation aluminumn alloy and rod type deformation aluminum alloy’s the yield strength and plastic roughly the same trend in the high temputure.The alloy drop the yield strength and plastic with the increase of temperature, the diameter is 50mm of rod type deformation aluminum alloy’s the yield strength and plastic more than the diameter is 80mm of tube type deformation aluminumn alloy when temputure less than or equal to 200℃.Not only has yield phenomenon but also the diameter is 50mm of rod type deformation aluminum alloy’s the yield strength and plastic less than the diameter is 80mm of tube type deformation aluminumn alloy when temputure is 250℃or 300℃.The tube type deformation aluminumn alloy’s the yield strength and plastic less than tube type deformation aluminumn alloy’s.更多还原