Exploring ‘Consolidation Factor’ in Materials: Impact on Microstructure, Phases and Performances

Abstract

The contribution of different types of strains (e.g., lattice strain, thermal strain, doping induced strain) are well known for crystalline materials. In this article we explain the effect of shaping induced strain, that exists in a multi-dimensional shaped body (in contrast to its free powder form). We define this as consolidation factor and illustrate its pivotal influence in overall phase, composition and microstructural development of various ceramic and allied materials. A closest analogy of this effect could be related to sized-induced phase transformation in free powder systems. To validate the impact of consolidation factor two common heat-treatments (i.e., sintering of the powder compact, and calcining the free powder of same composition under same sintering condition) has been carried out throughout the study. The findings establish consolidation factor as a critical mechanism influencing phase stability, particularly in doped zirconia, where it restricts the formation of the deleterious monoclinic phase and stabilizes tetragonal and cubic structures at lower dopant concentrations. The influence of this factor was also validated in many other material systems, such as, BaTiO3, BaCO3, and TiO2. A comparative analysis between sintered ceramics and calcined powders reveals that uniaxial compaction-induced stress fields modulate dopant distribution, grain boundary mobility, and phase transformation kinetics, impacting both phase purity and grain growth behavior. In-situ and ex-situ XRD, Raman spectroscopy, and microstructural investigations confirm that the consolidation factor critically governs strain-mediated phase evolution, offering new insights into optimizing nanoceramic processing for enhanced functional and structural performance.