Coating of ferritic stainless steel with Ni3Al intermetallic by self propagating high temperature synthesis (SHS)

In this thesis, specimens from AISI 430 ferritic stainless steel were coated with Ni3Al intermetallic by Self Propagating High Temperature Synthesis (SHS) method and the effects of process parameters on the microstructures of the coated layer and interface were investigated. With this purpose, Al and Ni powders (1/3 atomic ratio) were mixed homogenously in a mechanical mixer with ceramic balls at 16 rpm for 24 hours. Then the mixed powder, 1 mm in thickness was cold compacted on the stainless steel bars of 1 mm diameter and 10 mm height with the pressures of 150, 200, 250 and 300 MPa. The compacted specimens were ignited in a chamber under argon atmosphere by applying a force of 40 kN. Since it was seen that in situ coating was not possible, the specimens were annealed at 1000 and 1100 C for 45 minutes immediately after ignition. It was concluded that the time and temperatures were enough for a sound interface and coating. In the first chapter of the study, the subject is introduced. In the second chapter a literature research was given on the materials and the method (SHS) itself. In the third chapter, the experimental studies, materials and method were presented. In the fourth chapter the results and in the fifth and last chapter conclusion and recommendations are given. Keywords: SHS; Ni3Al, coating, intermetallic