根据超高速冲击理论,从磨粒与工件材料碰撞的角度研究了超高速磨削现象。为研究在超高速磨削条件下的磨屑形成机理,使用真实的人造金刚石和CBN颗粒作为磨料,将其粘接在7.62mm的子弹头部,利用81式步枪作为加速、加载装置,分别对碳素钢、天然大理石、弹簧钢和高速工具钢四种材料进行了720m/s的超高速冲击磨削试验,得到了若干有价值的超高速磨削的试验结果,并对试验结果进行了详细的分析。试验结果表明,在超高速冲击作用下,弹着点会产生瞬间高温,达到或超过材料的熔点,从而使子弹与钢板相接触区域的材料形成流动相,流动物质在磨粒和冲击波的作用下离开基体而形成磨屑。由此发现了超高速磨削冲击成屑现象,从更深的层面研究和揭示了超高速磨削的成屑机理,验证了“超高速磨削准流动相冲击成屑模型”的正确性。
According to the theory of ultra-high speed shock, the phenomenon of ultra-high speed grinding from the collision between grain and workpiece is researched. In order to study the chip formation mechanism in ultra-high speed grinding, the experimental study on ultra-high speed shock grinding about four kinds of the engineering material such as carbon steel, natural marble, spring steel and high speed tool steel are performed, which is used veritable amorphous carborundum and CBN grains that adhered to the head of bullet whose size is 7.62 mm as abrasive material, and used the 81 type rifle as accelerator and charger. Some valuable results in experiment of ultra-high speed grinding are acquired and the results are analyzed in detail. The experimental results indicate that in ultra high speed shock grinding the contact point is produced high temperature instantaneously which attached or exceeded its melting point, thereby, the material of the contact zone between the bullet and the steel plate becomes mobile phase and the flow material leaves the matrix and becomes abrasive dust under the action of the grain and shock wave. The phenomenon on chip formation due to shock of ultra-high speed grinding is found, so the chip formation mechanism due to shock of ultra-high speed grinding is studied and disclosed from the deeper level, and the accuracy of "the model of mechanism of chip-formation due to shock in quasi-fluid phase on super-high speed grinding" is verified.