Abstract
This article shows how percolation theory provides a theoretical model for the onset of shape distortion in liquid-phase sintering. The model uses an equivalent bond number per grain, with bond strength depending on the relative intergrain bond size. Based on this study, shape distortion is resisted by a rigid compact, which depends on the solid grains forming an infinite chainlike structure that spreads throughout the system. A sufficient condition requires contiguity above a critical value to form an infinite chainlike structure. The critical value is near 0.38. This is in good agreement with experimental results obtained with the W-Ni-Fe system sintered both under microgravity and on Earth. The effect of the gravitational force on the sufficient condition to avoid shape distortion is not significant. The effect of gravitational field on shape distortion becomes apparent only after the start of distortion, determining the final profile of a distorted compact.
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Liu, J., Upadhyaya, A. & German, R.M. Application of percolation theory in predicting shape distortion during liquid-phase sintering. Metall Mater Trans A 30, 2209–2220 (1999). https://doi.org/10.1007/s11661-999-0033-9
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DOI: https://doi.org/10.1007/s11661-999-0033-9