Experimental study on cutting temperature and cutting force in dry turning of titanium alloy using a non-coated micro-grooved tool

摘要

Various non-coated micro-grooves with 7-149 μm in depth and 0.14-0.50 in aspect ratio are proposed on tool rake surfaces along cutting chip flowing. The objective is to understand how the micro-groove shape and size influence cutting temperature and cutting force in dry turning of titanium alloy. First, the micro-grinding with a diamond wheel V-tip was employed to fabricate accurate and smooth micro-grooves; then dry turning experiments were performed with regard to material removal rate; finally, cutting temperature, cutting force and tool wear were investigated. It is shown that these micro-grooves patterned on tool rake surface contribute to decreasing cutting chip frictions and excluding cutting heat. The micro-grooved tool decreases cutting temperature by 103℃ and more against traditional plane tool. The predicted cutting tip temperature reaches about 1322℃ for traditional plane tool, but it does only about 500℃ for micro-grooved tool. Moreover, the cutting temperature decreases and the shear angle increases with decreasing micro-groove depth except for the case of 7 μm in micro-groove depth. The 25-μm-depth micro-grooved tool decreases cutting temperature and cutting force more greatly in larger material removal rate turning. In the dry turning with a micro-grooved tool, it is required that the microgroove width is less than cutting chip width and its aspect ratio is enough large to maintain the air spaces between chip back surface and tool rake surface.