Research On Workpiece Materials' Adiabatic Shearing Susceptibility In Cutting Process

Adiabatic shearing is a kind of plastic localization deformation when the material is loaded under the condition of high strain and high strain rate. Adiabatic shearing occurs on many kinds of workpiece materials in cutting process. On one hand, the occurrence of adiabatic shearing in the cutting process may cause the vibration of cutting force, and have some bad influences on the materials'machinability. On the other hand, it may be the sign of the chip rupture which will contribute to the automatic machining. Adiabatic shearing has both positive and negative influence in cutting process, so it is necessary to do some research on materials'adiabatic shearing susceptibility in order to use the materials with high adiabatic shearing susceptibility when adiabatic shearing is needed,and use the materials with low adiabatic shearing susceptibility when adiabatic shearing is avoided.Orthogonal cutting experiment was conducted on hardened 45 steel. Through the observation on the metallography of chip morphology, the influence of the cutting speed and cutting thickness on materials'adiabatic shearing susceptibility was studied. The cutting force is measured and recorded by the piezoelectric dynamometer. The influence of cutting speed and cutting thickness on cutting force is discussed. Based on the critical condition of adiabatic shearing, the influence of materials'characters on adiabatic shearing susceptibility was studied. Using hardened 45 steel as a reference, titanium alloy, aluminum alloy, zinic alloy, copper and brass, pure iron and steel, tungsten alloy, pure tantalum and tantalum alloy's adiabatic shearing susceptibility collected from other documents was qualitatively analyzed. Using energy barrier as the symptom of adiabatic shearing susceptibility, materials'adiabatic shearing susceptibility was quantitatively analyzed. According to the result of quantitative analysis, some regular patterns were summarized.