is cooled to room temperature to effect final transformation of the high temperature phase for a round ti 6al 4v bar surface heated by induction to a temperature in the beta phase field a final microstructure comprising a central core subjected to relatively low temperature of essentially the starting microstructure a surface layer of transformed beta microstructure specific morphology depends on the cooling rate immediately after induction heating and a transition zone between the two regions obtains heat treatments in demonstration of the invention were performed on 3 inch diameter by 3 inch long billets of ti 6al 4v alloy having starting microstructure consisting of 10 micron equiaxed alpha grains surrounded by a small amount of transformed beta the billets were heated within induction coil 11 fig1 with power supply 13 operating at 4 khz and 25 kw depth d for ti 6al 4v using p 75 u00d7 10 6 ohm in corresponding to peak temperature of about 2100 u00b0 f is about 0 43 inch and contains 1 67 lb of billet material using a heat capacity of 0 10 kwh lb at 2100 u00b0 f and coupling efficiency of 0 4 the required heating time to reach 2100 u00b0 f t sub u03b2 280 u00b0 f is about 0 0167 hours 60 sec in demonstration heat treatments of 55 to 65 second duration temperature sensitive crayon markings on the billet surfaces indicated that the peak surface temperature was 2050 u00b0 to 2150 u00b0 f after the samples cooled metallographic.