镍-纳米氧化镥复合电铸工艺及铸层性能研究

发布时间：2018-03-01 19:33

本文关键词： 复合电铸稀土显微硬度耐腐蚀性抗高温氧化性　出处：《吉林大学》2017年硕士论文　论文类型：学位论文

【摘要】：近年来,随着科学技术和制造工艺水平的不断进步,电铸技术向着复杂化、精确化、高性能化的方向快速发展。纳米Lu_2O_3微粒具有较高的密度和熔点,高温稳定性以及优异的耐热性,是一种较为理想的纳米微粒添加物,在陶瓷材料、发光材料和钨及其合金的添加物等领域已有广泛的应用,并取得了一定成果。将纳米Lu_2O_3微粒与金属镍共沉积,有望获得综合性能优异的复合铸层,因此研究纳米氧化镥复合电铸技术对提高电铸制品的性能及扩大电铸技术的应用范围具有重要意义。本文首先通过正交试验确定了Lu_2O_3微粒添加量、阴极电流密度及搅拌速率等三个工艺参数对复合铸层中的Lu_2O_3微粒共沉积量影响的显著性:Lu_2O_3微粒添加量影响最大,搅拌速度次之,阴极电流密度影响最小;并发现在工艺参数Lu_2O_3微粒添加量为4g/L、搅拌速率为800rpm、阴极电流密度3A/dm2时,可得到较高的Lu_2O_3微粒共沉积量(2.99wt%)。对复合铸层的表面形貌和粗糙度研究结果显示超声搅拌前处理能明显改善复合铸层的表面形貌;Lu_2O_3颗粒共沉积量越高,铸层越平整致密,表面粗糙度越小。由X射线衍射仪(XRD)分析可知,Lu_2O_3微粒的加入改变了复合铸层的择优取向。其次对不同Lu_2O_3微粒共沉积量的复合铸层的显微硬度、耐腐蚀性和抗高温氧化性等性能研究结果表明:Ni-Lu_2O_3复合铸层的显微硬度随着Lu_2O_3微粒共沉积量的增加而增加,铸层的显微硬度最高达到351.2HV,比纯镍铸层提高了33.1%;随着阴极电流密度和搅拌速率的增大,铸层的显微硬度均呈先增加后减小的趋势。Lu_2O_3微粒共沉积量为2.99wt%时,复合铸层的耐腐蚀性和抗高温氧化性能最好。为了进一步提高复合铸层性能,本文探索了LuCl3的加入对复合电铸工艺及复合铸层性能的影响,结果表明:LuCl3的加入提高了铸层中Lu_2O_3微粒共沉积量,LuCl3添加量为2g/L时,复合铸层表面最致密均匀,粗糙度最小,达到0.149μm。复合铸层的显微硬度随着LuCl3添加量的增加而先增加后减小,LuCl3添加量为3g/L时,铸层显微硬度达到403.1HV,比纯镍提高了53%。LuCl3添加量为2g/L时,复合铸层表面致密,缺陷较少,使其具有最好的耐腐蚀性能和抗高温氧化性能。
[Abstract]:In recent years, with the continuous progress of science and technology and manufacturing technology, electroforming technology has developed rapidly in the direction of complexity, precision and high performance. Nanocrystalline Lu_2O_3 particles have high density and melting point. Because of its high temperature stability and excellent heat resistance, it is an ideal nano-particle additive. It has been widely used in ceramic materials, luminescent materials, tungsten and its alloys. Some results have been obtained. The composite casting layer with excellent comprehensive properties can be obtained by co-deposition of nano-sized Lu_2O_3 particles with nickel metal. Therefore, it is of great significance to study the nano-Lutetium oxide composite electroforming technology to improve the properties of electroforming products and to expand the application range of electroforming technology. Firstly, the amount of Lu_2O_3 particles added is determined by orthogonal test. The effect of cathode current density and stirring rate on the codeposition amount of Lu_2O_3 particles in composite casting layer is significant. The effect of adding amount of Lu_2O_3 particles in composite layer is the biggest, the stirring speed is the second, and the influence of cathode current density is the least. It is also found that when the process parameter Lu_2O_3 particle is added 4 g / L, the stirring rate is 800rpm, the cathode current density is 3A / dm2, A higher amount of co-deposition of Lu_2O_3 particles can be obtained. The surface morphology and roughness of the composite casting layer are studied. The results show that the surface morphology of the composite cast layer can be improved obviously by ultrasonic stirring treatment. The higher the amount of co-deposition of LuSZ _ 2O _ 3 particles, the more smooth and compact the cast layer is. The smaller the surface roughness is, the lower the surface roughness is. The results of X-ray diffractometer show that the addition of Lu2O3 particles changes the preferred orientation of the composite cast layer. Secondly, the microhardness of the composite cast layer with different amount of co-deposition of Lu_2O_3 particles is obtained. The results of corrosion resistance and high temperature oxidation resistance show that the microhardness of the Lu_2O_3 composite cast layer increases with the increase of co-deposition amount of Lu_2O_3 particles. With the increase of cathode current density and stirring rate, the microhardness of cast layer increased first and then decreased. When the codeposition amount of Lu2O3 particles was 2.99 wt%, the microhardness of cast layer reached 351.2 HVV, which was higher than that of pure nickel cast layer, and the microhardness of cast layer increased firstly and then decreased with the increase of cathode current density and stirring rate. The corrosion resistance and high temperature oxidation resistance of the composite casting layer are the best. In order to further improve the properties of the composite casting layer, the effect of the addition of LuCl3 on the composite electroforming process and the properties of the composite casting layer is explored in this paper. The results show that the surface of the composite cast layer is densest and uniform, and the roughness is the least when the addition of Lu_2O_3 particles to the cast layer increases the amount of co-deposition of Lu_2O_3 particles in the cast layer is 2 g / L, and the addition amount of LuCl3 in the cast layer is 2 g / L. The microhardness of the composite cast layer increased first and then decreased with the increase of LuCl3 content. The microhardness of the cast layer reached 403.1 HV.When the addition of pure nickel was increased by 53. LuCl3 to 2 g / L, the surface of the composite cast layer was compact and the defects were less. It has the best corrosion resistance and high temperature oxidation resistance.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ153.4

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