Microstructure and mechanical property of Ti and Ti6Al4V prepared by an in-situ shot peening assisted cold spraying

In the current study, for the first time, an in-sity shot peening (SP) is introduced into cold spray by mixing large sized stainless steel particles with spraying powders to prepare dense Ti6AI4V (TC4) and commercially pure Ti (CP Ti) deposits. It is attempted that via the in-situ hammering by these large sized SP particles, plastic deformation of the previously deposited layers could be greatly enhanced and thereby porosities can be declined. Results show that, as the SP particle proportion increases from 0 to 70 vol.%, porosities of the CP Ti and TC4 coatings decrease from 13.7% and 15.3% to 0.3% and 0.7%, respectively. SEM observations reveal that no SP particle is incorporated into TC4 coatings. A few SP particles (<= 2.3 vol.%) are observed in CP Ti coatings clue to the relatively low hardness of CP Ti Only a slight decline trend in deposition efficiency of the CP Ti and TC4 powders is detected as increasing SP content. The in-silts SP results in remarkable work hardening. As the SP particle content increases from 0 to 70 vol.%, Vickers microharclness of the CP Ti and TC4 coatings increase from similar to 143 and 240 HV0.3 to similar to 203 and 427 HV0.3, respectively. (C) 2015 Elsevier Ltd. All rights reserved,