Modeling of Transient Thermal Conditions in Cutting
Modeling of Transient Thermal Conditions in Cutting作者机构:Laboratory for Machine Tools and Production Engineering R WTHAachen University Aachen 52056 Germany Fraunhofer Institute for Production Technology IPT R WTH Aachen University Aachen 52074 Germany
出 版 物:《Journal of Mechanics Engineering and Automation》 (机械工程与自动化(英文版))
年 卷 期:2017年第7卷第3期
页 面:113-119页
学科分类:080503[工学-材料加工工程] 07[理学] 08[工学] 0805[工学-材料科学与工程(可授工学、理学学位)] 0802[工学-机械工程] 080201[工学-机械制造及其自动化] 0702[理学-物理学]
主 题:Metal cutting infrared thermography heat sources transient temperature fields model based on Green's functions.
摘 要:The thermal conditions like the temperature distribution and the heat fluxes during metal cutting have a major influence on the machinability, the tool lifetime, the metallurgical structure and thus the functionality of the work piece. This in particular applies for manufacturing processes like milling, drilling and turning for high-value turbomachinery components like impellers, combustion engines and compressors of the aerospace and automotive industry as well as energy generation, which play a major role in modern societies. However, numerous analytical and experimental efforts have been conducted in order to understand the thermal conditions in metal cutting, yet many questions still prevail. Most models are based on a stationary point of view and do not include time dependent effects like in intensity and distribution varying heat sources, varying engagement conditions and progressive tool wear. In order to cover such transient physics an analytical approach based on Green's functions for the solution of the partial differential equations of unsteady heat conduction in solids is used to model entire transient temperature fields. The validation of the model is carried out in orthogonal cutting experiments not only punctually but also for entire temperature fields. For these experiments an integrated measurement of prevailing cutting force and temperature fields in the tool and the chip by means of high-speed thermography were applied. The thermal images were analyzed with regard to thermodynamic energy balancing in order to derive the heat partition between tool, chips and workpiece. The thus calculated heat flow into the tool was subsequently used in order to analytically model the transient volumetric temperature fields in the tool. The described methodology enables the modeling of the transient thermal state in the cutting zone and particular in the tool, which is directly linked to phenomena like tool wear and workpiece surface modifications.