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

研究了无孔弹性铝粉砂轮的移动热源热修形工艺，其结合剂的耐热性明显低于陶瓷结合剂砂轮。采用PVA粘结砂轮强制干涉的方法去除树脂粘结剂，已用于APPLE砂轮的修整，但在修整效率、切削能力等方面还存在一些问题。以YAG激光为热源，对由磨粒和树脂粘结剂组成的树脂棒进行激光修锐或扫描，分析了树脂表面的相变、形状、磨粒安装刚度等基本现象，并在此基础上，研究了YAG激光修整树脂结合剂砂轮和PVA结合剂砂轮的磨削特性，证明了YAG激光修整树脂结合剂砂轮的可行性。主要结论如下：（1）激光辐照时，树脂结合剂的转变、磨粒的释放和结合剂的汽化依次发生。（2）随着激光功率密度的增大或激光辐照时间的延长，热影响区的深度和直径增大。(3)As磨粒安装在热影响表面中更靠近梁中心，磨粒安装的刚度降低。（4）树脂砂轮的热修整可改善磨削表面粗糙度，降低磨削力，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.