【作者】 武志斌；

【导师】 徐鸿钧；

【作者基本信息】 南京航空航天大学 ， 机械制造及其自动化， 2002， 博士

【摘要】 制约高效磨削潜力和它在难加工材料中推广应用的关键是弧区磨削高温和工件烧伤。在深入研究高效磨削时弧区热作用机理的基础上，本文在国内外首次提出了渴望从根本上解决这一难题的两项基本对策，即研制高锋利度砂轮以大幅度降低磨削比能减少磨削热的产生和引入高压水射流冲击强化弧区换热效果以最大限度地疏导已经产生的积聚在弧区的磨削热。基于以上两项对策，本文完成以下创造性工作： 1．深入研究高效深切磨削弧区换热机理和工件发生烧伤的成因，在此基础上，借鉴热工领域的强化传热思想，提出采用高压水射流冲击强化磨削弧区换热过程解决高效磨削瓶颈的创新构想，设计采用径向定向高压水射流冲击强化冷却弧区工件表面的独创方案。 2．在研究磨削弧区换热机理的基础上，构思设计磨削弧区径向定向高压水射流冲击换热的实施方案，研制实现这一方案的工艺装置并在反复实验的基础上改进完善这一装置，使其能方便地应用于工业生产。 3．在分析多层砂轮和单层电镀砂轮缺点的基础上，研究钎焊单层超硬磨料砂轮的工艺优势、优异的磨削性能和绿色制造特性，分析国外钎焊单层超硬磨料砂轮的现状和存在的主要技术问题，提出研制起点高于国外的高锋利度单层钎焊超硬磨料砂轮以减少磨削热的产生解决高效磨削瓶颈的创新构思。 4．研究高温钎焊的基础理论，磨料与钎料、金属基体之间的浸润性、界面扩散化合的热力学基础、钎料组分、磨料镀膜与否以及钎焊工艺等等，为最终实现磨料、钎料和基体之间的高强度化学冶金结合探索出一套方法和规律。 5．分别设计了Ag-Cu合金和Ni-Cr合金钎焊单层金刚石砂轮的实验方案，并在实验室条件下分别进行了两种钎料钎焊单层金刚石砂轮取得成功。 6．对钎焊金刚石砂轮的界面进行了金相和理化测试分析，结果在国内外首次证明了界面上确有化合物生成，实现了化学冶金结合，而且检测出了化合物的具体结构。 7．在对立方氮化硼(CBN)钎焊性分析的基础上，在国内首次研制了能浸润CBN的钎料 AgcU－Ti合金钎料，并进行了钎焊 CBN的实验研究，测试结果表明 Ag（U－T合金对CBN表现出根好的浸润性并形成了高强度的冶金结合。其机理是合金中的Ti与CBN表面的B反应生成了Ti。 吕．在系列实验的基础上，研制出具有最佳地貌的高峰利度单层钎焊超硬磨料砂轮，使其磨料、基体和钎料具有永不脱落的化学冶金结合，并保证磨料的出露高度达到磨粒本身高度的70．80％，结合层厚度均匀一致，金刚石在钎焊过程中不受损伤。并与电镀砂轮进行了对比实验，结果单层钎焊金刚石砂轮显示出优异的磨削性能，在相同的磨削用量条件下，单层钎焊金刚石砂轮产生的磨削热少的多，磨削温度明显降低。 本项研究从控制减少磨削热的产生和疏导散逸已产生的磨削热的角度开拓了高效磨削研究领域的两个极富潜力的重要研究方向，进一步完善此项研究不仅渴望大幅度开发现有高效磨削的潜力，解决高效磨削的瓶颈，而且还可望有效解决当前尚无法解决的难加工材料的高效磨削间题，其技术经济意义十分重大。更多还原

【Abstract】 The difficult (bottleneck) problem of high efficiency grinding is high grinding temperature and burn which impose restriction on useful of high grinding in hard cutting materials. On the basis of the study on the mechanism of heat transfer in the grinding contact zone, two basic countenneasures are advanced to solve the difficult problem and further develop the potentiality of high efficiency grinding. One is increasing the sharpness of the grinding wheel for decreasing the specific grinding energy so as to reducing grinding heat as fully as possible. The other is the intensified cooling technology of radial and directional jet impingement in the grinding zone to steadily control the temperature of work-piece surface at extremely low lever under the heat flux far exceeds the critical value, put the heat scattered as fully as possible. Bases on the two creative countenneasures, following creative works in this paper are carried out1. On the basis study of the mechanism of heat transfer in the grinding contact zone, an creative conception is set up to exploit the potentialities of high efficiency grinding to great extent through enhancing heat transfer of the grinding zone, and according to this conception, an unique method is conceived and designed to intensify the cooling of the work-piece surface in the contact zone through high-pressure radial jet impinging.2. A new grinding fluid provided equipment is put forward to enhance heat transfer of the grinding zone by the high-pressure jet impingement. The structure of the experimental device is designed ingeniously. It successfully solves the difficult problems of rotational mechanical sealing and leak when the high-pressure grinding fluid is pumped into the grinding wheel parts which rotates at high speed, and restricting high-pressure grinding fluid radial and directional impingement to the work-piece surface in the contact zone. Maker the equipment further improvement and perfect, let it can be sues widespread in industries.3. On the basis study of the insufficient of traditional multiplayer and electroplating grinding wheel, study the technology superiority and specific property of green manufacturing. Analyses the presentsituation and main technology problem of brazing grinding wheel in the world. A new creative idea of researching and producing high quality starting brazing grinding wheel than other country is put forward.4. Study the bases theory of high temperature brazing and thermodynamic theory of interface element diffusion and chemical bond as well as infiltration of abrasive and brazing material-, steel base, study composition of brazing material > film of abrasive and technology . It can explore a series method and regular for finishing high strength chemical and metallurgical bond of abrasive ? brazing material and steel base at last.5. Design the experimental scheme of brazing diamond grinding wheel with Ag-Cu alloy and Ni-Cr alloy. The high temperature brazing of diamond grits under the condition of laboratory has met success with the two types of braze alloys. Ni-Cr alloys are mainly suitable the brazing of high efficiency grinding wheels and Ag-Cu alloys are mainly suitable the brazing of ordinary grinding wheels.6. The micro-region of the interfacial section between brazing alloy and diamond has been measured and analyzed by SEM-EDS and SEM-WDS as well as X-ray diffraction. It fist revealed that there exits chemical and metallurgical bond, and the structural types of interface carbide between brazing alloy and diamond particles has also been found out firstly.7. On the basis of studying the brazing of CBN, research and produce Ag-Cu-Ti alloy which can infiltrate CBN firstly in china, and make experiment studying ; the result show Ag-Cu-Ti alloy has high quality infiltration to CBN , Interfacial section have formed chemical and metallurgical bond between CBN and Ag-Cu-Ti.8. On the bases of a series experiment, a high sharp diamond grinding wheel has been developed ; it reached chemical and metallurgical bond of abra更多还原