电化学加工YT15硬质合金表面形貌特征实验研究

发布时间：2018-02-23 23:02

本文关键词： 电化学加工硬质合金腐蚀机理电解液微观形貌轮廓特征　出处：《大连理工大学学报》2017年04期 　论文类型：期刊论文

【摘要】：由于所含碳化物粉末与黏结金属的电极电位差等原因,硬质合金电化学加工的阳极表面蚀除过程较碳钢和其他金属更为复杂.以YT15硬质合金为实验对象,对试件原始表面进行统一加工条件下的研磨处理,使之具有一致的表面状态.在此基础上进行电化学加工实验,以SEM图像结合轮廓曲线,分析表面微观形貌的横向特征和纵向特征,获得表面材料溶解的特点和规律.实验发现,使用不同电解液获得的表面微观形貌特征差异显著,加工过程中的表面微观形态和腐蚀规律及变化特性也各不相同.研究认为,不同电解液产生的不同阳极表面膜特性和硬质合金材料固有的多组分特征是导致这种差异的原因,抑制硬质合金同类材料的边界腐蚀是获得良好加工效果的关键.NaOH去钝化能力较强,溶解速度快,适于成型加工电解液;NaNO_3及NaCl具有良好的钝化成膜能力,阳极膜无序破坏容易导致不均匀腐蚀,纯电化学加工不容易获得良好的加工效果,但通过合理施加外力控制阳极膜的有序破坏,则可提高表面质量,具有作为复合光整加工电解液的潜力;H_2SO_4+H_3PO_4成膜较均匀,活化作用较好,具有抑制材料不均匀溶解的能力,适用于具有一定表面质量要求条件下同时达到特定成型效果的加工.
[Abstract]:Because of the difference of electrode potential between carbide powder and bonding metal, the etching process of anode surface in electrochemical machining of cemented carbide is more complicated than that of carbon steel and other metals. Taking YT15 cemented carbide as experimental object, The original surface of the specimen was ground under uniform processing conditions to make it have a consistent surface state. On this basis, electrochemical machining experiments were carried out, and the SEM image was combined with the contour curve. After analyzing the transverse and longitudinal characteristics of surface morphology, the characteristics and rules of surface material dissolution were obtained. The micro-morphology, corrosion law and variation characteristics of the surface are different in the process of processing. It is considered that the characteristics of different anode surface film produced by different electrolytes and the inherent multicomponent characteristics of cemented carbide materials are the causes of the difference. Restraining the boundary corrosion of the same cemented carbide materials is the key to obtain good processing effect. NaOH has strong passivation ability and fast dissolution rate. It is suitable for forming electrolyte NaNO3 and NaCl with good passivation ability. The disordered destruction of anodic film can easily lead to uneven corrosion and the pure electrochemical machining is not easy to obtain good processing effect. However, the surface quality can be improved by controlling the orderly destruction of the anodic film by applying reasonable external force. H2SO4H3PO4 has the potential as electrolyte for composite finishing process. It has the advantages of uniform film formation, better activation, ability to inhibit the uneven dissolution of materials, and suitable for processing with certain surface quality requirements and achieving a specific forming effect at the same time.
【作者单位】：大连工业大学机械工程与自动化学院;西安永电电气有限责任公司;大连理工大学机械工程学院;康涅狄格大学;
【基金】：国家自然科学基金资助项目(51275062,51675072) 大连市科技计划项目(2015A11GX025)
【分类号】：TG135.5;TG662

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