{'fraction_non_alphanumeric': 0.024255788313120176, 'fraction_numerical': 0.024255788313120176, 'mean_word_length': 5.532374100719425, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Effect of LiYO2 addition on sintering behavior and indentation properties of silicon nitride ceramics

Abstract The influence of the sintering additive LiYO2 (5– 15 wt.%) on sintering behavior, microstructure and mechanical properties of Si3N4 ceramics was investigated. Since LiYO2 enables densification of Si3N4 at extraordinarily low temperatures, sintering was carried out in the range from 1200– 1700 °C. Densification was found to be enhanced with increasing additive content due to an increasing volume fraction of the liquid. The phase transformation and grain growth occurred through a solution-reprecipitation mechanism, where the precipitation took place preferentially on pre-existing β-Si3N4 nuclei (of which the starting powder already contained 20 wt.%). The indentation fracture toughness increased with both sintering time and additive content as a result of the growth of elongated grains.