Production of Aluminium Powdered Poreless Elastic Wheel and Development of Dressing Techniques with Moving Heat Source

本研究的目的是建立一种移动热源的铝粉状无孔弹性（APPLE）轮的热修整技术，该技术的粘接材料的耐热性明显低于玻璃化粘接轮。采用PVA结合剂砂轮强制干涉的方法机械去除树脂结合剂，对APPLE砂轮进行了修整，但在修整效率、切削能力等方面还存在一些问题。本文采用单脉冲CW:YAG激光作为热源照射或扫描磨料颗粒与树脂结合剂组成的树脂棒，了解激光修整的基本现象，分析树脂表面的转变、轮廓、颗粒安装刚度等。在这些基础数据的基础上，验证了YAG激光修整技术的有效性，研究了YAG激光和PVA结合剂砂轮共同修整树脂类结合剂砂轮的磨削特性。本文的主要结论如下：(1)在激光照射下，树脂类键的转变、磨粒的释放和键合材料的汽化依次发生。(2)热影响结构的深度和直径随着激光功率密度和照射时间的增加而增加。(3)在热影响表面上，磨料粒越靠近光束中心，磨料粒的刚度越低。(4)对树脂砂轮进行热修整可以改善磨削表面粗糙度，减小磨削力，延长砂轮寿命。

The purpose of this study is to establish a thermal dressing technique with moving heat source for aluminium powdered poreless elastic (APPLE) wheel, in which heat resistance of bonding material is markedly lower than that of vitrified bond wheel. Mechanical removal of resinoid bond by means of forced interference with PVA bond wheel has been used for dressing of APPLE wheel, but some problems remain as to dressing efficiency, cutting ability and so on. In this report, a single pulse of CW:YAG laser introduced as a heat source is irradiated or scaned on resinoid stick made up of abrasive grain and resinoid bond to make clear a fundamental phenomenon of laser dressing, analyzing transformation, profile of resinoid surface, stiffness of grain mounting and so on. On the basis of these fundamental data, availability of a dressing technique with YAG laser is proved, investigating grinding characteristics of resinoid bond wheel dressed with both YAG laser and PVA bond wheel. Main conclusions obtained in this report are as follows: (1)Transformation of resinoid bond, releasing abrasive grain and vaporization of bonding material take place in this order with laser irradiation. (2)The depth and diameter of heat affected structure increase with increasing power density or irradiating time of laser. (3)As an abrasive grain is mounted nearer to a beam center in heat affected surface, a stiffness of the grain mounting decreases. (4)Thermal dressing for resinoid wheel result in improvement of ground surface roughness, decrease of grinding forces and extension of the grinding wheel life.