Referring now to FIG 5, the radially outer wall 125 provides a substrate 198, which may first be first suitably prepared or treated, and then laser shock peened to produce an annular laser shock peened surface 54 and a pre stressed region 56 having deep compressive residual stresses imparted by laser shock peening extending into the radially outer wall 125 and {HEAD ~ the substrate} 198 from {TAIL ~ the laser shock peened surface} 
Referring now to FIG 5 , the radially outer wall 125 provides a substrate 198 , which may first be first suitably prepared or treated , and then laser shock peened to produce an annular laser shock peened surface 54 and a pre stressed region 56 having deep compressive residual stresses imparted by laser shock peening extending into the radially outer wall 125 and { HEAD ~ the substrate } 198 from { TAIL ~ the laser shock peened surface }
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