November_December_2021_AMP_Digital

FEATURE A D V A N C E D M A T E R I A L S & P R O C E S S E S | N O V E M B E R / D E C E M B E R 2 0 2 1 4 4 sults of a comparative analysis between the setpoint and actual temperatures at the ends of the holds (left) and ramps (right) for various DCGQ schedules. Ideally, to make design and analysis of the DCGQ process simpler and more intuitive, the setpoint and actual temperatures should be equal at the end of each temperature ramp and hold. For the processes shown in Fig. 6, HR4 and HR7 abide to this equality, but as the ramp and hold times get shorter, these two temperatures begin to deviate; HR5 had the shortest ramp and hold times. This fact does not negate the use of modeling in recipe design, but rather solidifies the fact that processing equipment behavior should be thorough- ly understood, within normal operating conditions, if the process is to be modeled. After the behavior is understood, Fig. 8 — Comparison of experimental and simulation results for one DCGQ recipe. 9 Fig. 9 — Microstructure of a carburized coupon processed using (a) DCGQ and (b) HPGQ, magnified 1000X. (a) (b) it can be incorporated into the models for more accu- rate results. Figures 7 and 8 show time-temperature results com- paring the DANTE simulation, which used the single HTC and relevant ambient temperatures determined from ex- periments, and the actual time-temperature data. In addi- tion to the two tests shown in this article, five more recipes were executed, with their data also used in characterizing the DCGQ equipment. There is good agreement between simulation and experimental results, with the tests not shown having similar agreement. Each DANTE model of the DCGQ process used the same HTC, but the ambient temperature varied depending on the temperature ramp and hold times of the given recipe. 10