Simultaneous spray deposition and peening of metals (SSP)

AbstractA new process, simultaneous spray peening (SSP), is described which comprises the spray deposition of metals together with simultaneous shot peening. This combined incremental operation allows either thick or thin deposits to be made in ferrous or non-ferrous metals. The deposits are hot worked and densified during the process so improving their properties compared with more conventional spray deposits. An additional advantage is that the inherent residual tensile stresses of spray deposition are counter-balanced by the compressive stresses caused by peening. By control of the simultaneous peening operation it is shown that the residual stresses in SSP deposits can be maintained at any required positive or negative level. Examples and structures are shown of SSP products made from gas-atomized melts, by arc spray, and by plasma spray.