Microstructure and interfacial strength of stainless steel coatings obtained by thermal spray process

The present investigation has been conducted to study the adhesion of X10CrMnNil8-8- 5 austenitic stainless steel (ASTM 301) coatings deposited on two different substrates of aluminum alloys such as AG3 (ASTM 5754) and AU4G (ASTM 2017A) by using arc spraying process (APS). The structure, microstructure and phase composition coatings were analyzed by SEM, EDS and XRD. The adhesion tests were carried out using 4-point bending tests. The SEM showed that the dense microstructures of ASTM 301 coatings have a homogeneous lamellar morphology w ith the presence of porosities and unmelted particles. The XRD spectrum of coatings revealed the main phase corresponding the solid solution as face-centered cubic (fee) structure and also the presence of small proportion of the metastablc form y-Fe2G3 and FeO oxides. The microhardncss of coatings is near four times than the two substrates of aluminum alloys. The 4- point bending tests results showed that the critical interfaclal fracture energy GIC of the composite system B namely (ASTM 2017A/75F. bond coat/ASTM 301) is three times greater than the composite system A (ASTM 5754/75E bond coat/ASTM 301).