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2.1.3 Cutting heat and temperature 2.1.3.1 Generation and transmission of cutting heat2.1.3.2 Cutting temperature 2.1.3.3 Influence factors on cutting temperature 2.1.3.1 Generation and transmission of cutting heat Cutting heat comes from the conversion of cutting energy. As shown in Fig.2.35, the general cutting heat Q includes Qpthe hear from shear deformation energy, Qfthe heat from the chip-tool friction, and Qfthe heat from machined surface tool friction. The general cutting heat Q can be decomposed into chip heat Qch, tool heat Qc, workpiece heat Qw and surrounding medium heat Qf, . There is the relation : Qp+Qf+QfQch+Qw+Qc+Qf (2.20) 2.1.3.2 Cutting temperature Through the balance of the deformation energy, friction energy generated in the cutting region and heat transmission, the cutting temperature may be calculated approximately. Taking the calculation of average temperature in the cutting region as an example: In a unit time the generated heat q is equal to the dissipated cutting power Pm, that is q=Fzvc/60 W (2.21) Here Fz main cutting force (N); vc cutting speed (m/min) (1) Calculation of cutting temperature The temperature increment resulting from q is related to the materials density and specific heat capacity c:Here p per unit cutting force (N/m2) c specific heat capacity (J/kgK) density (kg/m3).cpbhvCvFDDccZ (2.22)2.1.3.2 Cutting temperature 2.1.3.2 Cutting temperature 750刀具二维切削中的温度分布 工件材料：低碳易切钢； 刀具：o=30，o=7； 切削用量：ap=0.6mm， vc =0.38m/s； 切削条件：干切削， 预热611C When cutting plastic material, the maximum Temp is near the tool tip of the rake face. When cutting brittle material, the maximum Temp is near the tool tip of the flank.2.1.3.2 Cutting temperature There are several methods of measuring cutting temperature such as thermoelectric couple, heat radiation, coloring and infrared method etc. Among them the thermoelectric couple finds wide application. Natural thermoelectric couple Synthetic thermoelectric couple2.1.3.3 factors Influencing cutting temperature Cutting temperature principally depends on the amount of heat generated in the cutting process, also on the amount of heat dissipation. There are several Influence factors on cutting temperature : tool geometric parameters 、cutting parameters、work material .(2) Measurement of cutting temperature2.1.3.2 Cutting temperature Experiential formulaZyxcpC vfa刀具材料加工方法高速钢车削1401700.350.450.20.30.080.10铣削80钻削150硬质合金车削320f (mm/r)0.10.410.150.050.20.310.30.26切削温度的系数及指数2.1.3.3 factors Influencing cutting temperature vc（m/min）切削速度、工件材料对切削温度的影响1GH131 21Cr18Ni9Ti 345钢(正火) 4HT200刀具材料：YT15；YG8刀具几何参数：o=15，o=68，r=75，1= -10，s=0，b=0.1mm，r=0.2mm切削用量：ap=3mm，f=0.1mm/r（）103050709011013040060080010001243Discussion:The geometry of the cutting tool:The workpiece materialThe tool wearThe cutting fluid
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