Al3Ti-7075复合材料论文原位制备铝基复合材料的热处理.doc

Al3Ti/7075复合材料论文：原位制备铝基复合材料的热处理工艺及力学性能研究【中文摘要】与传统的金属材料相比,铝合金及其复合材料具有比强度、比刚度高、加工成形性好、尺寸稳定性强和耐腐蚀性好等一系列优点,所以在汽车、电子、航空航天等工业领域具有极其广阔的发展前景。本文采用高能超声辅助原位反应法制备Al3Ti/7075铝基复合材料,解决了传统方法下制备的复合材料中增强颗粒分布不均匀与及增强颗粒与基体界面结合不好等问题。对制备的铝基复合材料显微组织、物相及力学性能进行分析,结果表明：Al3Ti增强颗粒在基体中分布均匀,晶粒组织细小,Al3Ti颗粒与基体界面结合良好。为进一步提高复合材料的力学性能,采用箱式热处理炉、显微硬度器、SEM电镜、能谱分析仪对Al3Ti/7075复合材料固溶和时效处理进行分析,结果表明：复合材料的单级固溶处理的最佳方法为480/5h,复合材料经此条件固溶处理后,第二相能够较好的回溶到基体内且不会发生晶粒长的的现象。随着固溶温度继续升高,溶质原子溶入有限,溶质原子带来的强化效果不大,合金硬度有下降的趋势,当固溶温度达到520时,出现了组织过烧现象。复合材料的双级固溶处理最佳方法为440/3h+480/2h,与单级固溶处理相比,复合材料在此条件下固溶处理后,复合材料能够达到最大固溶度,第二相回溶更充分且硬度达到固溶处理最大值。进而对复合材料时效行为进行分析,结果表明：基体合金和复合材料在同一温度下时效时,复合材料到达时效峰的时间要比基体合金短；在同一温度下,之所以Al3Ti/7075铝基复合材料的硬度值要比基体的高,主要是因为采用了高能超声法,使复合材料晶粒细化及原位反应生成的Al3Ti颗粒能够均匀分布在基体中。采用M-2000型磨损实验机、扫描电镜和电子天平对铸态Al3Ti/7075复合材料及基体进行干摩擦滑动磨损实验,结果表明：复合材料和基体的磨损现象都是若干种磨损机理的综合作用的结果；随着摩擦速度和载荷的增加,复合材料和基体的磨损率逐渐升高；从整体上来讲,在同一摩擦条件下,复合材料的耐磨损性能高于基体；在低载荷磨损时,由于复合材料中增强颗粒的存在,使得复合材料磨损性能要比基体好；随着载荷加大,增强颗粒会松动,从基体中脱落或者断裂,这势必减少了摩擦接触面积,断裂的其他部分仍在基体中起到增强作用从而提高复合材料的磨损性能。【英文摘要】Compared with the traditional metal material, aluminum and composite materials have a series of advantages:specific strength than stiffness, good formability, dimensional stability, strength and corrosion resistance, so it is extremely broad prospects for development in the automotive, electronics, aerospace and other industries field.This paper adopts high-energy ultrasound in situ prepared AI3T1/7075 matrix composites, prepared under the traditional method to solve the composite materials with enhanced uniform particle distribution and to enhance the bonding between particles and other issues. On the preparation of the aluminum matrix composite micro structure and mechanical properties of phase analysis showed that:Al3Ti reinforcing particles distributed uniformly in the matrix, grain size small, Al3Ti particles and the bonding is good.To further improve the mechanical property of composite, the solution and aging treatment of Al3Ti/7075 composite was analyzed with box heat treatment furnace, microhardness device, SEM and EDS. The results showed that:composite materials, the best single-stage solution treatment method is 480/5h, composite materials after solution treatment for this condition, the second phase can be a good solution back to the base body and the grain does not occur long phenomenon. The higher solution temperature, dissolved solute atoms is limited, the strengthening effect of solute atoms do not bring the alloy hardness of a downward trend, when the solution temperature reaches 520, the emergence of the phenomenon of organized burn.The best way of two-stage solution treatment is 440/3h+480/2h. Compared with single-stage solution treatment, composite materials in this condition, after solution treatment, composite materials maximum solubility, the second phase back to more fully dissolved solution treatment and maximum hardness. Aging behavior of the composites were analyzed, the results showed that:the matrix alloy and composites at the same temperature aging, the composite material to reach the peak aging time shorter than the matrix alloy; the hardness of Al3Ti/7075 aluminum matrix composites higher than the matrix, mainly because of the high-energy ultrasound used to make composite materials, grain refinement and in situ reaction of Al3Ti particles can be uniformly distributed in the matrix.Dry sliding wear behaviour of extruded Al3Ti/7075composites and 7075 matrix were investigated with wear test mechine,electronic balance and SEM, the results show that:several abrasion mechanism result in the wear of composite and matrix alloy; with the rise of sliding speed and load, the wear rates of composites and matrix increase; In the same friction condition, the wear performance of composites higher than the matrix; At low load wear in composite material, due to the existence of reinforcing particles that composites wear performance is better than matrix; As the load increased, enhanced particles fracture or loose from the matrix, which is bound to reduce the friction contact area, breaking the rest of the play is still the matrix enhancement to improve the wear properties of composite materials.【关键词】Al3Ti/7075复合材料 7075铝合金 固溶处理 时效处理 磨损性能【英文关键词】Al3Ti/7075 composites 7075 aluminum alloy Solution treatment Aging treatment Wear mechanism【目录】原位制备铝基复合材料的热处理工艺及力学性能研究摘要3-5ABSTRACT5-6第1章 绪论10-261.1 引言10-111.2 铝基复合材料发展概况11-131.2.1 复合材料的概念及性能特点111.2.2 铝基复合材料的主要类型11-121.2.3 铝基复合材料的性能特点121.2.4 铝基复合材料的发展与其应用12-131.3 颗粒增强铝基复合材料制备方法13-161.4 高能超声制备金属基复合材料的研究现状及前景16-191.4.1 超声波的定义及其发展状况16-171.4.2 超声波在制备颗粒增强金属基复合材料的声学效应17-181.4.3 超声波制备颗粒增强金属基复合材料研究现状18-191.5 铝基复合材料的热处理19-211.5.1 Al-Zn-Mg-Cu系铝合金常用热处理制度19-201.5.2 铝合金热处理工艺的发展现状201.5.3 颗粒增强铝基复合材料热处理概述20-211.6 金属基复合材料摩擦磨损研究发展现状21-251.6.1 概述21-221.6.2 复合材料磨损性能的参数221.6.3 颗粒增强铝基复合材料摩擦磨损性能的影响因素22-251.7 本课题的研究意义和主要内容25-26第2章 实验方法26-342.1 引言262.2 实验材料的选择26-282.2.1 基体材料26-272.2.2 增强颗粒的选择272.2.3 复合材料制备方法27-282.3 Al3Ti/7075铝基复合材料热处理方法28-302.3.1 固溶处理28-292.3.2 时效处理29-302.4 Al_3Ti/7075铝基复合材料磨损实验方法30-312.4.1 复合材料磨损实验方法302.4.2 磨损试样检测与分析方法30-312.5 检测方法与分析设备31-342.5.1 组织分析设备312.5.2 铝基复合材料力学性能测试设备31-322.5.3 铝基复合材料热处理设备32-332.5.4 热处理试样检测与分析方法33-34第3章 7075铝基复合材料热处理工艺研究34-493.1 引言343.2 超声制备Al3Ti/7075铝基复合材料的组织形貌34-353.3 单级固溶对复合材料组织和性能的影响35-403.3.1 不同固溶温度对复合材料显微组织影响36-383.3.2 不同固溶时间对复合材料显微组织影响38-403.4 双级固溶对复合材料组织和性能的影响40-433.4.1 第二级固溶温度和时间对复合材料硬度的影响40-423.4.2 双级固溶后X射线衍射图谱42-433.5 复合材料的时效处理强化行为43-463.5.1 时效处理分析433.5.2 复合材料时效处理的显微组织43-443.5.3 复合材料时效处理的显微硬度44-453.5.4 复合材料时效强化微观机理分析45-463.6 不同状态下基体与复合材料硬度的比较46-473.7 本章小结47-49第