Elevated Temperature Properties of Short Fiber Reinforced Aluminum.
Abstract
Recently two new reinforcing fibers have been developed. They are the very small SiC whiskers produced from rice hulls, an inexpensive by-product of the food processing industry, and graphite fiber mats produced directly from pitch without an intermediate yarn precursor. SiC/2024 Al and G/2024 Al composites with 21 volume percent reinforcement were manufactured by pressure casting ingots with random fiber orientations and then warm extruding the ingots to get a good degree of fiber alignment. For comparison purposes, a unreinforced 2024 Al control was subjected to the same thermomechanical treatment. Tensile properties were evaluated over a temperature range from room temperature to 380 C (720 F). The G/Al had poorer mechanical properties than unreinforced Al because there was excessive fiber breakage during extrusion. SiC/Al had a Young's elastic modulus and a specific elastic modulus which were both 50 percent greater than the values for wrought aluminum at temperatures up to 300 C (570 F). At temperatures less than 200 C (390 F), the SiC reinforced composite had 30 percent greater yield strength and fifteen percent greater tensile strength than the Al control. These SiC/Al data are encouraging because of the low projected cost of the whiskers, the economics associated with manufacturing composites by casting and extrusion, and the ease with which the composite can be cut using conventional steel tools.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1977
- Accession Number
- ADA047409
Entities
People
- L. S. Weinman
- W. L. Phillips
Organizations
- United States Naval Research Laboratory