The improvement of wear characteristics of aluminum through the addition of silicon via laser processing

Engine weight reduction is a primary concern to automotive manufacturers regardless of the size of the vehicle. Engine blocks made from aluminum reduce weight, but result in excess engine wear. One possible solution is Laser Induced Surface Improvement (LISI) applied directly to the cylinder wall. It was hypothesized that through the LISI process a aluminum-silicon hypereutectic alloy could be created with significant improvements in wear resistance over unprocessed aluminum. Here an attempt has been made to investigate, through a series of tests, the optimal silicon content for improvement of wear characteristics of aluminum A319. Flat coupon trials were conducted using various processing conditions and precursor compositions. Performance was evaluated and ranked through metallurgical analysis and bench wear testing. Once an optimal precursor was chosen, limited duration testing was conducted on a 13 cubic inch aluminum air-cooled single cylinder to demonstrate performance in an engine environment and compare to parent bore test results. Through this study, it was shown that LISI is a viable option for producing wear resistant surfaces on aluminum cylinder bores.