Microstructural and elemental characterization of pumice-bauxite-clay ceramics: effects of sintering temperature and scherrer-based analysis

This study aims to evaluate the influence of sintering temperature on the crystallographic features and elemental distribution of pumice-bauxite-clay based ceramic materials using standard characterization methods (XRD, SEM, EDS) and computational analysis via the Scherrer equation. The primary goal is to determine how varying sintering temperatures affect crystal size, microstrain, and elemental homogeneity-parameters that indirectly reflect potential structural performance under high-temperature conditions. The ceramic composition consists of 20% pumice, 40% bauxite, and 40% clay. The slip-cast material was sintered at three different temperatures: 1100 degrees C, 1200 degrees C, and 1250 degrees C. For the ceramic samples, microstructural analysis were carried out using SEM, elemental composition was determined by EDS, and phase identification was performed via XRD. Crystal size and microstrain values of the sintered ceramic samples were calculated using the Scherrer equation in Python, supported by NumPy, Pandas, and Matplotlib. Crystal sizes ranged from 65.36 nm to 110.65 nm, and microstrain values from 0.0065 to 0.0373 epsilon, depending on temperature and peak positions. At 1250 degrees C, mullite and quartz phases were most mature and uniformly distributed, with the highest crystal sizes (similar to 103.5-110.6 nm) and lowest microstrain (similar to 0.0065-0.0096 epsilon), indicating better microstructural stability. EDS maps showed more homogeneous Si and Al distribution and reduced porosity at higher temperatures. Although mechanical tests of the samples were not performed, improved crystallinity and phase uniformity at 1250 degrees C suggest enhanced thermal and mechanical performance. These findings underline the potential of pumice and bauxite as alternative ceramic raw materials, supporting resource efficiency and high-temperature application performance.

Journal

JOURNAL OF THE AUSTRALIAN CERAMIC SOCIETY

Year

2026

Volume

62

Issue

1

Pages

135-151

ISSN

2510-1560

eISSN

2510-1579

DOI

10.1007/s41779-025-01242-8

WoS UID

WOS:001536899800001