模具材料等离子喷焊制备陶瓷覆层试验研究

发布时间：2018-04-22 22:05

本文选题：模具 + 覆层　；参考：《中北大学》2015年硕士论文

【摘要】：模具作为“工业之母”，其寿命问题长期受到业界人士的广泛关注。提高模具模腔表面的耐腐蚀性，耐磨性热，，抗酸碱性，和抗氧化性，同是降低模具的热应力是解决模具寿命的关键。本文通过实验试图找到强化模腔表面的最优材料，来减缓模腔表面的破损。实验采用的制备技术为等离子喷焊。本文首先提出了课题的意义，并总结了模具的各种失效形式；然后介绍了本文涉及到的喷焊技术的原理，研究现状以及发展。第二部分主要介绍两部分，包括实验材料的选择和实验方案的制定。选W6Mo5Cr4V2高速钢和C45钢为基体；合金粉末选用Ni60粉和stellite6粉；工作层粉未选用SiC，Cr3C2和WC。将合金粉末Ni60和三种陶瓷粉末分别以7：3、8：2、9：1的比例混合，制成九种粉，喷焊在W6基体上。选用stellite6和stellite6+SiC（stellite6：SiC=7:3）粉末作为C45钢的喷焊材料。第三部分介绍了喷焊实验，采用LU-F500-F600型等离子喷焊机，试件在喷焊前进行打磨除油的过程。喷焊后经过线切割，镶嵌，粗磨，精磨，腐蚀，最终得到待测的金相试件。第四部分对试验六个方面的对比分析。首先对三种不同的粉末进行了宏观形态，截面显微结构，显微硬度，热膨胀系数，比热容和热导率的比较，得到的结论是30%WC，10%Cr3C2和30%WC粉末得到的覆层有利于缓解模具的热应力。接着是对30%SiC，10%Cr3C2，30%WC覆层进行对比分析。硬度方面，WC覆层的表面硬度为900HV左右，这与基体的硬度很相近，并没有达到强化基体的目的；而SiC和Cr3C2粉末的喷焊层硬度都达到了1000HV以上，这明显高于基体的硬度，达到了强化基体的目的。从热物性角度分析，30%的SiC制备的覆层最能满足模具的工作要求。第五章针对C45钢等离子喷焊实验进行了分析，主要从宏观形态，微观显微组织，显微硬度和热膨胀系数方面进行了比较。结果显示单一的stellite6粉末无法达到强化材料表面的目的，加入SiC可以有效的提高材料表面性能。综上所述：Ni60+SiC比例为7：3的粉末在W6钢表面喷焊的效果是最好的。在C45钢stellite6+30%SiC可以显著增强覆层表面的性能。
[Abstract]:Mould as the "mother of industry", its life-span has long been widely concerned by the industry. To improve the corrosion resistance, wear resistance, acid and alkali resistance and oxidation resistance of mold cavity surface is the key to solve the die life. In this paper, we try to find the best material for strengthening the cavity surface through experiments to reduce the damage of the cavity surface. Plasma spray welding is used in the experiment. This paper first puts forward the significance of the subject, and summarizes the various failure forms of the die, and then introduces the principle, research status and development of the spray welding technology involved in this paper. The second part mainly introduces two parts, including the selection of experimental materials and the formulation of experimental scheme. W6Mo5Cr4V2 high speed steel and C45 steel were chosen as matrix, Ni60 powder and stellite6 powder were used as alloy powder, and no sic Cr 3C 2 and WC C were used as working layer powder. The alloy powder Ni60 and three kinds of ceramic powder were mixed in the ratio of 7: 3: 8: 2: 9: 1 to make nine kinds of powder, which were sprayed on the W6 substrate. Stellite6 and stellite6 SICP stellite 6: sic 7: 3) powders were used as spray welding materials for C45 steel. In the third part, the experiment of spray welding is introduced. The process of polishing and removing oil before spray welding is carried out by using LU-F500-F600 plasma spray welding machine. After spray welding, wire cutting, inlay, rough grinding, grinding, corrosion, and finally get the metallographic specimen to be tested. The fourth part is the comparative analysis of six aspects of the experiment. Firstly, the macroscopic morphology, cross section microstructure, microhardness, thermal expansion coefficient, specific heat capacity and thermal conductivity of three kinds of powders were compared. The conclusion is that the coating of 30WC10Cr3C2 and 30%WC powder is beneficial to alleviate the thermal stress of the mould. Then a comparative analysis is made on the coating of 30 sic and 10 Cr 3 C 2 + 30 WC. The surface hardness of WC coating is about 900HV, which is close to the hardness of matrix, and the hardness of SiC and Cr3C2 powder is higher than that of 1000HV, which is higher than that of substrate, and the hardness of spraying layer of SiC and Cr3C2 powder is higher than that of substrate, which is similar to the hardness of matrix, and the hardness of spraying layer of SiC and Cr3C2 powder is higher than that of substrate. The purpose of strengthening the matrix is achieved. From the point of view of thermal physical properties, the coating prepared by 30% SiC is the best to meet the working requirements of the mould. In the fifth chapter, the plasma spray welding experiments of C45 steel are analyzed, mainly from the aspects of macroscopic morphology, microstructure, microhardness and coefficient of thermal expansion. The results show that the single stellite6 powder can not strengthen the surface of the material, and the addition of SiC can effectively improve the surface properties of the material. In conclusion, the effect of spray welding on the surface of W6 steel is the best when the ratio of: Ni60 SiC is 7:3. The surface properties of the coating can be significantly enhanced by stellite6 30%SiC in C 45 steel.
【学位授予单位】：中北大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG174.4

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