TIME AND LENGTH CORRECTIONS IN ANALYSIS OF INITIAL STAGES OF DIFFUSION-CONTROLLED SINTERING

All models of the initial stages of sintering assume instantaneous heating of the shrinkage specimens to the sintering temperature. However, the time to reach the sintering temperature and the accompanying shrinkage can seriously affect the apparent shrinkage‐time dependence that is used to identify the shrinkage mechanism. The thermal expansion of unsintered compacts is shown to be identical with that calculated from published thermal expansion coefficients. The correct initial hot length of a shrinkage compact is therefore the cold length corrected for thermal expansion. The time to heat a shrinkage specimen was measured and is identical with both the calculated heating time and that determined by extrapolating a length vs. time plot to the initial hot length. The length and time corrections obtained from this extrapolation are compared with those obtained by the methods of Johnson and Cutler and of Anderson. Copyright © 1969, Wiley Blackwell. All rights reserved