In the field of welding as it applies bonding dissimilar alloys hsa been done with limited testing in the automotive field. Using a process called MPW or magnetic pulse welding alu. and steel aloys have been bonded. However given the low temperature of alu alloys in most cases (1250 F) to melt as opposed to alot of steel alloys including stainless which is much higher. A tig weld would most likely fail and you would be scraping the alu. off the floor.