Investigation of the Effect of Temperature on the Microstructural and Mechanical Properties of the Ultra-High Temperature Ceramic Composite ZrB2-SiC-TiC Using the Multi-Step Spark Plasma Sintering Method
Year: 2024
Type: article
Abstract: The sintering of ZrB2 presents significant challenges due to its covalent bonding and the high temperatures required for the process. Prior research has demonstrated that incorporating up to 20% by volume of SiC as an additive can enhance both the sintering process and the mechanical properties of ZrB2-based composites. The objective of this study was to fabricate and characterize an ultra-high temperature ceramic composite composed of ZrB2 containing 20 vol. % SiC, utilizing the Spark Plasma Sintering (SPS) method with a multi-step approach at various temperatures. Additionally, the study sought to investigate the influence of a TiC additive on the microstructural evolution and mechanical properties of the composite. The research focused on assessing the impact of sintering temperature, ranging from 1600°C to 1900°C under a pressure of 30 MPa, in the presence of a 10 vol. % TiC additive. The introduction of up to 10% by volume of TiC into the ZrB2-20 vol. % SiC composite, followed by sintering at 1800°C for 5 minutes, resulted in the formation of (Zr,Ti)B2 and (Ti,Zr)C solid solutions within the matrix. These solid solutions, along with reactions involving surface oxides such as ZrO2 and B2O3, contributed to a 15% increase in relative density. Furthermore, notable enhancement was observed in the mechanical properties, including a 14% increase in hardness, a 12% increase in elastic modulus, a 20% increase in fracture strength, and an 8% increase in fracture toughness. A comparative analysis with previous studies revealed that employing a multi-step SPS technique, as opposed to a single-step process, significantly reduced the temperature and time of the process to achieve a relative density exceeding 99%. However, it was also observed that increasing the maximum sintering temperature to 1900°C in the ZrB2-20 vol. % SiC-10 vol. % TiC composite resulted in excessive grain growth and a slight decrease in relative density by approximately 1%.
Authors: Pourbahraini, S., Ahmadian, M.
Institution: Isfahan University of Technology
Language: English
Subfield: Ceramics and Composites
Field: Materials Science
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W4405141894