ALUMINUM SILICON CARBIDE COMPOSITE PROCESSED BY FIELD ASSISTED SINTERING TECHNIQUE: MICROSTRUCTURE AND MECHANICAL PROPERTIES
Open Access
- Author:
- Alagic, Sven
- Graduate Program:
- Materials Science and Engineering
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- February 27, 2019
- Committee Members:
- Jogender Singh, Thesis Advisor/Co-Advisor
Anil Kamalakant Kulkarni, Committee Member
Douglas Edward Wolfe, Committee Member - Keywords:
- aluminum
silicon
carbide
composite
metal
matrix
field
assisted
sintering
spark
plasma
high
volume
fraction
structural
aerospace
materials
science - Abstract:
- Aluminum is widely used in aerospace structural components because of its low cost, light weight, and high strength properties. Aluminum silicon carbide composites are an opportunity to reduce weight of these structural components without sacrificing strength. Aluminum and silicon carbide have similar densities (2.6 and 3.21 g/cm3 respectively), but silicon carbide has much higher hardness and strength. In this thesis, improved hardness, elastic modulus, yield strength, and ultimate tensile strength were achieved in an aluminum alloy based composite system by the addition of silicon carbide particles. Bulk baseline samples as well as samples containing various amounts of SiC were manufactured using Field Assisted Sintering Technology (FAST). Hardness was found to improve from 130 HV in ECKA Al-Alloy to 207 HV in Al Alloy with 40% SiC composite (60% improvement). This improvement was accompanied with an improvement in elastic modulus from 81 GPa in ECKA Aluminum Alloy to 126 GPa in Aluminum Alloy with 40% SiC (40% improvement). Yield strength improved from 211 to 417 MPa (97% improvement) and ultimate tensile strength improved from 308 to 472 MPa (50% improvement) for these materials. The microstructure of the samples revealed a homogeneous dispersion of silicon carbide particles throughout the aluminum matrix. The improvement in specific strength was 50% over the baseline aluminum alloy. The samples have been used as extrusion feedstock as a proof of concept for eventual structural applications.