FIELD ASSISTED SINTERING OF SILICON CARBIDE: EFFECTS OF TEMPERATURE, PRESSURE, HEATING RATE, AND HOLDING TIME
Open Access
- Author:
- Gephart, Sean Michael
- Graduate Program:
- Engineering Science
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- April 06, 2010
- Committee Members:
- Jogender Singh, Thesis Advisor/Co-Advisor
Jogender Singh, Thesis Advisor/Co-Advisor
Anil Kamalakant Kulkarni, Thesis Advisor/Co-Advisor
Ivica Smid, Thesis Advisor/Co-Advisor - Keywords:
- sintering
SiC
silicon carbide
ceramic
spark plasma sintering
field assisted sintering technology
SPS
FAST - Abstract:
- Several challenges still exist in sintering of silicon carbide (SiC) ceramic tiles due to high production cost associated with long sintering time at elevated temperatures and high rejection rates. This challenge is being addressed by exploring an emerging sintering technology called Field Assisted Sintering Technology (FAST), also known as Spark Plasma Sintering (SPS) and Pulse Electric Current Sintering (PECS), that will be an alternative manufacturing method in producing high-density ceramic tiles in minutes instead of hours or days with a minimum rejection rate. This research concentrated on utilizing FAST to produce dense SiC ceramic tiles and examine the sintering behavior of SiC with changing temperature, hold time, pressure, and heating rate. A preprocessed SiC powder with carbon and boron carbide additives and a mean particle size of 0.5 µm was used to produce the SiC ceramic tiles. The sintered ceramic tiles were then characterized for material properties. Material properties were plotted as a function of processing parameter, and optimum conditions were explored. SiC is an attractive light weight and structurally robust material that is resistant to high temperature and chemical reactivity. SiC parts and components are produced by compacting the powder material and sintering it together at high temperatures. SiC has been considered for a wide range of applications including high temperature gas turbines, cutting tools, thermally stable parts or coatings, chemically resistant parts or coatings, high temperature semiconductor devices, as well as others. Currently, SiC components are produced by conventional sintering processes that involve many steps including powder preparation, green sintering, and extremely long processing times which expose the material to elevated temperatures for an extended period of time. This research concentrated on circumventing the traditional processing techniques by utilizing the FAST process. Using the FAST process, this research showed that it was possible to sinter SiC in minutes rather than hours, to equivalent or greater densities. There was also no processing of powder or green sintering of any kind. The sintered ceramic tiles were characterized and the results showed the relationship between several material properties and the FAST processing parameters. Understanding this relationship will make it possible to tailor the material properties to fit the needs of a given application.