Machining by abrasion - General principles

Based on the use of abrasive grains, either loose or bonded to each other (grinding wheels) or to a support (strips, paper, etc.), abrasive machining operations are extremely varied.), abrasive machining operations are extremely varied: they range from the grinding of steel slabs or blooms produced by continuous casting, to the polishing of microelectronic circuits or high-resolution optical parts, to the manufacture or finishing by grinding of mechanical parts of all kinds (tools for shaping by plastic deformation of metals or injection of polymers, bearing parts, machine components, etc.), the sanding of wood, the polishing of marble and stone, the polishing of marble and stone, the polishing of marble and stone, the polishing of marble and stone, the polishing of marble and stone, the polishing of marble and stone, the polishing of marble and stone, the polishing of marble and stone, the polishing of marble and stone, the polishing of marble and stone, the polishing of marble and stone.), wood sanding, marble and granite polishing... Some authors estimate that the cost of grinding operations alone represents 20 to 25% of the cost of machining operations in an industrialized country. On the other hand, grinding is the only economical option for :

• machining of materials with very high hardness and/or brittleness: martensitic bearing steels, high-speed steels in the metallurgical state of use, refractory alloys, metal carbides, glass, ceramics, etc;

• produce the very low roughnesses (in the nm range) essential for certain optical, microelectronic and micromechanical applications...

Finally, it should be noted that the interactions between abrasive grains and the machined part are very similar to the interactions between rubbing parts, which lead to wear by abrasion, one of the most important modes of wear of shaping tools (rolling mill rolls, forging dies, spinning and drawing dies, etc.), machine components or manufactured products. The performance of abrasive machining processes is constantly improving, in line with growing industrial needs. However, despite their great economic importance, abrasive machining processes remain largely unknown and their scientific aspects poorly understood and mysterious.

This article, devoted to the mechanical aspects of abrasion, aims to provide an initial overview of scientific knowledge on this type of machining; readers can also refer to the specialist articles in this section for a more detailed description of how the various processes are implemented.