搅拌摩擦加工5083-H321铝合金板材的摩擦磨损性能研究

发布时间：2018-01-23 17:54

本文关键词： 5083-H321铝合金搅拌摩擦加工摩擦系数磨损量组织　出处：《广东工业大学》2012年硕士论文　论文类型：学位论文

【摘要】：采用搅拌摩擦加工(Friction Stir Process, FSP)技术对5083-H321铝合金板材进行处理,借助UMT-3型多功能摩擦磨损试验机,采用球-块式对偶往复摩擦磨损测试法,在室温干摩擦磨损试验条件下,对比性地研究了5083-H321铝合金轧制板材及其FSP处理后板材的摩擦磨损性能,探索了加载时间和载荷等参数对二者摩擦系数与磨损量的影响规律；借助扫描电子显微镜(SEM)及能谱仪(EDS),观察与检测了不同时间及载荷下的磨损面、磨屑及对偶摩擦面的形貌和化学成分,并进一步探讨了摩擦磨损机制；借助光学显微镜(OM)、背散射电子衍射分析仪(EBSD)及取向显微成像分析技术(OIM)等手段,分析了FSP对5083-H321铝合金板材组织特征的影响规律,探讨了FSP技术对改善其摩擦磨损性能的机理。主要内容与结果如下： 1.探明了5083-H321铝合金板材与FSP处理后板材试样的摩擦系数随时间、载荷的变化规律。在初始滑动阶段,即0-600s内,两者的摩擦系数均较为平稳,但FSP5083的摩擦系数较早出现下降,并且其平均摩擦系数略小于5083-H321的平均摩擦系数；随滑动时间的增长,即600-1500s内,两者的摩擦系数均逐渐减小并趋于接近；在载荷分别为20、30、35及40N下的初始滑动阶段,FSP5083的平均摩擦系数均略小于5083-H321的平均摩擦系数,但在整个滑动时间段内,载荷的影响规律不明显。FSP加工可减低5083-H321铝合金板材的表面摩擦系数。 2.探明了5083-H321铝合金板材与FSP处理后板材试样的磨损量随时间、载荷的变化规律。随滑动时间的增长,两者的总磨损量均增加,在逐个时间段内,两者的磨损量逐渐减少,且FSP5083的总磨损量明显小于5083-H321的总磨损量,两者的磨损量差值先增大,在600s时达到最大后逐渐减小；两者的磨损量随载荷的增大而明显增加；FSP加工对5083-H321铝合金板材的耐磨性有明显的改善作用。 3.研究了5083-H321铝合金板材与FSP处理后板材试样磨损表面与磨屑的形貌特征,并对摩擦磨损过程中的作用机制进行了探讨。两者的磨损面均出现了磨沟、翻边、凹坑、裂纹、碎屑等形貌特征；其中5083-H321铝合金板材的碎屑含量较多,FSP5083铝合金板材的塑性变形较为严重,磨屑均呈块状,磨屑体积随载荷的增加而增大；通过能谱分析发现摩擦副表面发生了氧化,以及出现了试样对摩擦对偶的粘附现象。磨损的主要作用机制为粘着磨损、磨粒磨损和疲劳磨损。 4.探明了FSP对5083-H321钒合金板材组织特征的影响规律,并对其成形机理进行了分析。FSP5083铝合金的成形性良好,无孔洞、裂纹等缺陷存在,由于热-力作用的差异,FSP5083铝合金组织可分为搅拌区、热力影响[区、热影响区和轴肩作用区等四个区域,各区具有不同于5083铝合金板材的组织特征,其中轴肩作用区的晶粒较5083-H321铝合金出现了明显的细化；5083-H321铝合金主要含有黄铜织构{110}-112和S织构{123}634等织构组分,经FSP处理后,织构主要转变为{11-2}1-10取向,同时在与板材轧面平行的摩擦面中,晶面(111)与摩擦面平行的晶粒的含量显著提高。 5.探讨了FSP加工改善5083-H321铝合金板材摩擦磨损性能的机理。磨损表面形貌特征表明摩擦磨损过程伴随着材料的塑性变形,轴肩作用区的细晶层可避免材料在此塑性变形过程中裂纹的过早形成和扩展的不利影响,可在一定程度上抑制疲劳磨损,同时可增强摩擦过程中对摩擦面的加工硬化效果,从而增强了抗粘着与磨粒摩擦磨损作用的效果；另一方面,由于(111)l品面为铝合金晶粒的的密排面,具有较低的表而能,能减小摩擦对偶与试样间的粘着系数。这两个因素是FSP改善5083-H321铝合金板材摩擦磨损性能的主要机制。
[Abstract]:The friction stir processing (Friction Stir, Process, FSP) of 5083-H321 Aluminum Alloy sheet processed by UMT-3 type multifunctional wear testing machine with dual ball block reciprocating friction and wear test method in friction and wear test at room temperature under dry conditions, comparative study of friction and wear properties of 5083-H321 Aluminum Alloy rolling after the treatment of FSP plate and plate, explore the loading time and load parameters on the two coefficient of friction and wear are analyzed; by means of scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS), and detected the observation of wear surface under different time and loads, wear debris and dual friction surface morphology and the chemical composition, the friction and wear mechanisms were discussed; by means of optical microscope (OM), electron backscatter diffraction (EBSD) and orientation imaging analysis technique (OIM) method, the effect of FSP on 5083-H32 The mechanism of the influence of the microstructure characteristics of 1 aluminum alloy sheet is discussed. The mechanism of FSP technology to improve its friction and wear properties is discussed. The main contents and results are as follows:
1. proven plate and FSP 5083-H321 Aluminum Alloy plate sample of friction coefficient with time and load variation. In the initial stage of 0-600s, sliding, the friction coefficient was relatively stable, but the friction coefficient of FSP5083 early decline, the average friction coefficient and the average friction coefficient is slightly less than 5083-H321; with the growth of the sliding time, namely 600-1500s, friction coefficient both decrease gradually and tend to be close in the initial load respectively; sliding phases 20,30,35 and 40N, the average friction coefficient of average friction coefficient FSP5083 were slightly less than 5083-H321, but in the entire period of sliding load, influence is not obvious in.FSP processing 5083-H321 can reduce Aluminum Alloy plate surface friction coefficient.
2. to determine the wear plates and FSP 5083-H321 Aluminum Alloy plate specimen with time variation of load. With the growth of the sliding time, the total amount of wear of both were increased in each time period, the wear loss decreased, the total amount of total amount of wear and wear FSP5083 significantly less than 5083-H321 the difference of wear both first increased and reached the maximum at 600s and then gradually decreases; the wear loss increases with load increasing obviously; have a significant role in improving the wear resistance of FSP processing on 5083-H321 Aluminum Alloy sheet.
3. on the plate with FSP 5083-H321 Aluminum Alloy plate wear surface and wear debris morphology, and the friction and wear mechanism was also discussed in detail. The wear surface of the two show the Mogou, flanging, pits, cracks, and other debris morphology; more debris content 5083-H321 Aluminum Alloy plate among them, the plastic deformation is a serious FSP5083 Aluminum Alloy sheet, debris was massive, debris volume increases with the increase of load; through spectrum analysis found that oxidation occurs on the friction surface, and the adhesion phenomenon of specimen on the friction pair. The main wear mechanisms are adhesive wear, abrasive wear and fatigue wear.
4. to determine the effect of FSP on the microstructure characteristics of 5083-H321 vanadium alloys, and the forming mechanism was analyzed by.FSP5083 Aluminum Alloy good formability, no holes, cracks and other defects, due to differences in thermal stress, FSP5083 Aluminum Alloy can be divided into stir zone, heat affected area, four area of heat affected zone and the shoulder area, the district has characteristics different from the 5083 Aluminum Alloy sheet, wherein the grain shoulder area is 5083-H321 Aluminum Alloy appeared obvious refinement; 5083-H321 Aluminum Alloy mainly contains {110}-112 brass texture and S texture and {123}634 texture components, after FSP treatment, the main texture change the {11-2}1-10 orientation, at the same time with the sheet rolling surface parallel to the friction surface, crystal face (111) and the content of the grain is parallel to the surface of friction increased significantly.
5. of FSP 5083-H321 Aluminum Alloy plate processing to improve the mechanism of the friction and wear performance. The wear surface morphology characteristics show that the friction and wear process with the plastic deformation of materials, fine grain layer of the shoulder area can avoid the material in the plastic deformation process of the adverse effects of premature crack formation and expansion, can inhibit fatigue wear to a certain extent, also can enhance the friction process of friction surface hardening effect, thereby enhancing the anti adhesive and abrasive wear and friction effect; on the other hand, because of (111) l surface for the close packed plane of the Aluminum Alloy grain, has low surface energy, can reduce the adhesion the coefficient of friction between the dual and the sample. These two factors are the main mechanism of FSP improving 5083-H321 Aluminum Alloy plate friction and wear properties.

【学位授予单位】：广东工业大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH117.1

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