Laser Processing of Discontinuously Reinforced Aluminum Composites
Abstract
Discontinuously reinforced aluminum (DRA) composites have attractive potential as engineering materials due to the combination of good mechanical properties and relatively low cost; however utilization of these composites requires improved machining and joining procedures. In this study, the feasibility of laser cutting and laser beam welding of DRA composites was investigated. It was found that the DRA composites could be cut at rates faster than that of unreinforced aluminum. The SiC and Al203 reinforcement materials absorbed more energy than the monolithic aluminum at the C02 laser beam wavelength of 10.6 micrometers. The improved energy absorption leads to an increase in laser cutting rates and greater weld penetration over unreinforced aluminum, except in the case of silicon carbide whisker reinforced composites. The formation of aluminum carbide and the difficulties in removing the viscous dross lead to a lower cutting rate than of unreinforced aluminum. The focus of the laser beam welding experimentation dealt with eliminating the formation of aluminum carbide by filler metal additions. Appropriate filler metals and their respective carbides were analyzed for thermodynamic stability and compatibility in the weld. A computer program that determines the equilibrium of chemical systems was employed to predict the amount of titanium necessary to prevent the formation of aluminum carbide in the fusion zone of a Al/SiC/20 composite. The analysis determined that a 22 wt% addition of titanium to the fusion zone was necessary to prevent the formation of aluminum carbide. Laser processing, Composites, Reinforced aluminum, Machining joining, Cutting welding, DRA.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1994
- Accession Number
- ADA277903
Entities
People
- K. C.
- R. B. Bhagat
- R. P. Martukanitz
Organizations
- Pennsylvania State University