Search Results

In order to reduce the cost of manufacturing aluminum structures, the automotive and earth moving industries are looking at lasers, high speed machining, and plasma processes to cut holes and various shapes. Tower Automotive in conjunction with Caterpillar as part of a National Institute of Standards and Technology (NIST) funded program, studied the effects of various hole-making processes on the fatigue life of 6061-T6 aluminum. Another part of this program was to study the effects of various surface treatment procedures to increase the fatigue life by a factor of ten or higher. SAE keyhole specimens were made from 3mm and 6mm thick 6061-T6 aluminum. The center test hole was cut using punch pierce, O2 plasma, 4KW CO2 laser, 3KW YAG laser, and HyDefinition plasma. The fatigue testing indicated punch pierce cut holes had the highest fatigue life, while at almost all stress (load) levels, holes cut with CO2 laser had the lowest fatigue life.