Research On The Cutting Tools With Surface Microstructure Function And Turning Performance

Nowadays, titanium alloy has started applying to the high additional value industry because of its light weight and high specific strength, such as aviation, car and medical treatment, it is a kind of energy conservation and carbon emission reduction parts material.But, the titanium alloy turnings very difficult, because the titanium alloy has bad heat conduction and it is easy to take place chemical reaction with the cutter surface,stick to the cutter, accelerate the wear .Therefore, put forward to process a microstructural of micron dimensions on the rake face , will remove heat and chips quickly, carry out highly-efficient processing on titanium alloy.This thesis is going to discuss the structures of cutting tools, based on the study of titanium alloy (Ti-6A1-4V OR TC4), which is a typical difficult-machine-material.I process parallel array micro V-shape slot and oblique micro V-shape slot on the cutter rake face . Through analyzing the combination research of theories and experiments, I am going to compare the wear and tear of the cutting tools, the forms of the chips removal and chips forms, the work pieces processing surface roughness, to decide the grades of these alloy cutting tools. From the experiment research of turning titanium alloy with different microstructure surface functional alloy cutting tools, I get the following conclusions:First:When cutting titanium alloy in high speed, the smooth surface cutter's damage forms include rake face wear, tool nose wear, back face wear, slot wear,and tipping. The mainly wear mechanism is sticking wear,chemistry wear(oxidative wear, diffusive wear),slot wear and brittleness breakage;there is a uniform wear trace on the parallel micro v-shape slot cutter and oblique micro v-shape slot cutter, their damage forms include rake face wear, tool nose wear, back face wear, the mainly wear mechanism is chemistry wear and boundary wear.Second: The microstructure characteristic of cutter rake face is big influence on the cutter wear.Use model Auto CAD 2007 computer to calculate the proportion of wear and I get to know that the parallel micro v-shape slot cutter and oblique micro v-shape slot cutter are able to lighten the wear and tear, and the lighten percentages is about 9.09%, 15.3 and 9.4% ,15.4% .In addition, the tool nose breakage is more serious on the smooth surface cutter's than the other two cutters, but,there is few tool nose breakage on the oblique micro v-shape slot cutter.Third: In the aspects of chips length and chips form, chips of the smooth surface cutter is longer, the whole form appearances clique, but the parallel micro v-shape slot cutter's chips length is shorter, short strip in whole shape.The oblique micro v-shape slot cutter's chips length is shortest, grain form in whole shape.Their chips length is distinct from 67 mm, 24 mm, 7 mm on the average.Fourth: The test results show that cutting tools with parallel or oblique micro v-shape slot make positive effect in chips removal, heat elimination, cutting temperature depression, SWC control at the same time.Especially,the microstructure of oblique micro v-shape slot cutter is more obvious of improving surface roughness uniformity.Although the surface roughness for processing has no improvement, the parallel micro v-shape slot cutter and oblique micro v-shape slot cutter compare to smooth surface cutter can raise 41.7%,75.5% in the surface roughness uniformity respectively.Therefore, the adoption of microstructure surface functional high hardness alloy cutter can carry out highly-efficient processing on titanium alloy, this is an important basis for choosing the suitable cutter structure to process titanium alloy material, providing good industry prospects to develop the applied market of titanium alloy partses.