Effect of the TLP process parameters on microstructure, mechanical properties and corrosion resistance of 316L stainless steel to pure commercial titanium joint with pure copper interface

In this research, effect of time and temperature of TLP process on the microstructure, mechanical properties and corrosion resistance of CP-Ti to 316L stainless steel joint evaluated. For this purpose pure copper foil with 100 µm thickness was used as interlayer and joining process carried out at 950˚C, 1000˚C and 1050˚C and for 90, 120 and 150 minutes. After the joining process, shear and micro-hardness test and corrosion resistance were applied in the samples. The test results revealed that the shear strength of the sample 1000˚C is better than two other soaking temperatures. The main reason was the formation of less intermetallic compounds at the interface, as well as the presence of less athermally solidification zone area. Microstructural examinations for the sample after TLP at 950˚C revealed no iron and titanium bearing intermetallic compounds in the interface while for two other samples, there exist considerable amount of intermetallics in the microstructure. Corrosion test results showed that the resistance against corrosion depends on the intermetallic compounds formed in the interface. Intermetallic phases includes FeTi, TiCu, Ti2Cu, and TiCu2. The sample prepared at 1000˚C for 120 minutes had less intermetallic compounds and as a result, had the best corrosion resistance. Fe and Ti containing intermetallics had good corrosion resistance in simulated body fluid, as comparison with Ti and Cu containing compounds.