Al-Ni合金的制备及其组织、力学性能的研究

发布时间：2018-05-08 06:43

本文选题：Al-Ni合金 + 固溶时效　；参考：《合肥工业大学》2017年硕士论文

【摘要】：本文采用99.9 wt.%工业纯Al和99.999 wt.%的Ni粉,通过半连续铸造法制备出不同Ni含量的Al-x wt.%Ni合金(x=0.1和0.2)。对合金进行530°C×12 h的均匀化处理后,在600°C固溶温度下,研究不同保温时间对合金组织和力学性能的影响,随后对合金分别进行单级时效处理和应变时效处理。通过硬度测试、导电率测量、金相(OM)组织观察、扫描电镜分析(SEM)和能谱分析(EDS)等分析方法进行试样的组织结构性能表征研究。通过观察和分析Al-Ni合金铸锭的组织形貌和微观结构发现Ni元素能促进铸态晶的细化,之后选定600°C的固溶温度,测量Al-0.1Ni、Al-0.2Ni合金在固溶处理过程中合金硬度、电导率与保温时间的关系,结果表明:两种合金的硬度都是先升高后降低,其导电率随固溶时间的延长逐渐上升;同时还观察了固溶过程中合金组织和相结构的演变规律,经600°C×12 h固溶处理后,粗大初生相能最大程度地溶入基体。最后,对合金时效与冷轧时效处理进行比较和优化,将Al-Ni合金在600°C固溶12 h后,进行不同工艺参数的时效处理。结果表明250°C时效时,合金获得的峰值硬度最大;而40%、60%、80%不同冷轧形变量的时效处理中,硬度和电导率变化趋势与T6时效处理相同,硬度都是先增加到达峰值后降低,电导率略有升高。而T8的冷轧形变能促进Al3Ni等二次相的析出,有效缩短合金到达时效峰值的时间。Ni加入铝中部分合金溶入基体,而多余Ni元素则以金属间化合物的形式析出,Ni元素除了与Al形成Al3Ni二次相,同时还能与合金中的杂质元素生成Al9FeNi相,消除杂质Fe元素的不良影响。冷轧引入大量位错,合金强度明显提高。Al-0.1Ni合金形变峰值时效后综合性能最佳,时效制度为:80%冷轧变形+250°C×40 s,此时合金电导率为61.8%(IACS),硬度为46.34 HV、抗拉强度达133.29 MPa,仍保持较好的延伸率。
[Abstract]:In this paper, Al-x wt.%Ni alloy with different Ni content was prepared by semi-continuous casting with 99.9 wt.% industrial pure Al and 99.999 wt.% Ni powder. After homogenizing the alloy for 530 掳C 脳 12 h, the effect of different holding time on the microstructure and mechanical properties of the alloy was studied at 600 掳C solution temperature, and then the single stage aging treatment and strain aging treatment were carried out respectively. The microstructure and properties of the samples were characterized by means of hardness measurement, conductivity measurement, metallographic observation, scanning electron microscopy (SEM) and energy dispersive analysis (EDS). By observing and analyzing the microstructure and microstructure of Al-Ni alloy ingot, it is found that Ni element can promote the refinement of as-cast crystal, and then the solution temperature of 600 掳C is selected to measure the hardness of Al-0.1NiN Al-0.2Ni alloy during the process of solution treatment. The results show that the hardness of the two alloys increases first and then decreases, and the conductivity increases gradually with the prolongation of the solution time, and the evolution law of the microstructure and phase structure of the alloys during the solution process is also observed. After 600 掳C 脳 12 h solution treatment, the coarse primary phase can be dissolved into the matrix to the greatest extent. Finally, the aging treatment and cold rolling aging treatment of Al-Ni alloy were compared and optimized. The Al-Ni alloy was treated with different process parameters after 12 h solution at 600 掳C. The results show that the peak hardness of the alloy is the largest at 250 掳C aging, while the hardness and conductivity change trend is the same as that of T6 aging treatment with 80% different cold rolling variables, and the hardness increases first to the peak value and then decreases. The conductivity increased slightly. However, the cold rolling deformation of T8 can promote the precipitation of Al3Ni and other secondary phases, and effectively shorten the time when the alloy reaches the peak age. The superfluous Ni elements precipitate in the form of intermetallic compounds, which not only form Al3Ni secondary phase with Al, but also form Al9FeNi phase with impurity elements in the alloy, thus eliminating the negative influence of impurity Fe elements. When a large number of dislocations are introduced into cold rolling, the strength of the alloy increases obviously, and the comprehensive properties of Al-0.1Ni alloy after peak deformation aging are the best. The aging rate is 250 掳C 脳 40 s, the electrical conductivity is 61.8%, the hardness is 46.34 HVV, the tensile strength is 133.29 MPA, and the elongation is good.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG146.21

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