Research On Characteristics Of The Transition Of Ductile-Brittle In Laser And Ultrasonic Vibration Assisted Cutting Of Hard Alloy

Hard alloy is a kind of the metal composite material with high hardness, high wear resistance, high temperature resistance and other excellent characteristics. They are being used more widely in aerospace, optics and electronics field, and it also holds a extremely important status in the modern tool material, wear resistant materials as well as corrosion resistant material. However, because of its high hardness, strength as well as the poor capability of mechanical processing, the ductile mode machining of brittle materials is essential in the ultra precision machining process.Considering the influence of two dimensional ultrasonic vibration cutting parameters such as time,frequency and amplitude, this paper discuss the theory formula of the critical cutting depth on the two-dimensional ultrasound of laser assisted machining based on common cutting critical cutting depth. The study found that intermittent cutting of two-dimensional ultrasonic vibration cutting can change the tool parameters, reducing the cutting time, cutting force to increase of critical load and critical cutting depth; Composite ultrasonic vibration cutting speed can further changes cutting time and the shear angle in ultrasonic vibration dynamic cutting process, thereby increasing the critical depth of cut; Laser heating can improve the cutting temperature under certain conditions, so as to reduce the hardness of the material, and increase the critical depth of cut; After numerical calculation, critical cutting depth will increase with the cutting speed increasing, increases with the Co content increasing, and increases with the radius reducing; The critical cut depth of Two dimensional ultrasound assisted laser cutting is greater than ordinary cutting.Based on ultra precision lathe SPHER360 and simulation of cutting process and the characterization of the self built test platform, this paper have simulation cutting depth gradient characterization cutting test of the hard alloy material’s simulation cutting process such as YG10, YG15 and YG20 using the CBN tool. Through the white light interferometer observations scratch properties, estimation of critical cut depth, we study the change of the critical cut depth under different cutting conditions, and compared with the results of theoretical analysis. Experimental results show that the critical depth of cut ultrasound cutting is greater than the ordinary cutting under thesame cutting condition. Critical cutting depth increase with cutting speed and the content of Co increasing. It is consistent with the theoretical results.We have the actual cutting test based on the theory analysis and experiment on the removal characteristics of hard alloy material. Study found that in the process of YG10, YG15 and YG20 hard alloy material in common, material crushing rate and the machined surface roughness value decreases with cutting speed increasing. In the laser assisted machining process of two-dimensional ultrasound and two-dimensional ultrasound, the surface roughness value decreases with the increase of speed, but it has a certain degree of increase near the critical cutting speed. YG10, YG15 and YG20 hard alloy material below the critical depth of cut is found that the production of ductile removal and surface roughness of smaller, higher accuracy in the cutting process in practice,...