Neglecting heat carried away to the atmosphere. Therefore considering total heat generated during machining is carried away by chip, workpiece and tool.

$\therefore$ Heat generated = W.D = fc.vc = Heat carried by chip, w/p and tool.

Heat carried by chip = 75-80 % Heat carried by workpiece = 15-20 % Heat carried by tool = 5 to 8 %

From the above, amount of heat carried by tool is found very small and hence negligible. Therefore, whatever heat generated will be assumed to be carried by chip and work piece

W.D = Heat carried by chip and workpiece

Heat carried by chip = W.D - heat carried by work piece

m. cp $\triangle$T = w - a.w where a = 0.15 to 0.2

$\therefore$ m.cp $\triangle$T = w (1 - a)

$\therefore$ $\triangle$T = $\frac{fc.vc. (1-a)}{\zeta.Ao.vc.cp}$ ....... m. $\zeta$v = $\zeta$ mRR = $\zeta$.Ao.Vc

$\therefore$ $\triangle$T = $\frac{fc(1-a)}{s.Ao.cp}$

T chip = $\triangle$T + Room temperature

From above, temperature of chip is becoming greater than or equal to melting point of work piece.

From above fig, all 3 heat zone are melting at one point called tip of tool. therefore, tip of tool experience very high temperature. the temperature of tool goes beyond the hot hard ?? temperature of tool material. therefore, to avoid this process parameters should be controlled.

There are various methods of temperature measurement :

a) Tool work thermocouple

b) Radiation pyrometer

c) Erobeded thermocouple

d) Colorimetric method