Materials & Advanced Manufacturing (MAM)

Feasibility of Joining Wrought Homogenized Armor Steel with Friction Stir Welding

by William Evans; Antonio Ramirez; Martin McDonnell; Mike Eff


The United State Army employs several advanced armored combat vehicles, in a wide array of different environments, and applications. Armor steels are hard and are required to meet certain conditions to stay within the military’s specifications for armored steels. Vehicle armor is typically joined using arc welding methods. Joining via arc welding degrades armor material below specification, so alternate joining methods are being explored like Friction Stir Welding (FSW). FSW is a solid-state joining technique that utilizes a rotating pin to stir plasticized material and use a tool shoulder to forge the material into the joint. The advantages come from the reduction in peak temperature, an increase in mechanical performance, and a decrease in possible defects that occur. In this study FSW parameters were developed and used to weld Wrought Homogenous Armor (HRA) steel. The welds were subject to hardness indention, and metallographic analysis to observe an early prediction of joint properties. Through this work it was shown that HRA can be joined using FSW and the weld stir zone is similar in properties to the base metal.