Research On Superplastic Diffusion Bonding Of TC4 Titanium Alloy To 1Cr18Ni9Ti Stainless Steel

The titanium alloy has a lot of good function. It is one of the materials which is mostly used in the aviation, aerospace and many other fields. But its reserve is very limited and the price is expensive. These reasons limit its further generalization and application. Therefore, studying the conjunction of titanium alloy and stainless steel is significative for reasonably, efficiently and fully using titanium alloy and economizing the titanium alloy resources. It also develops a new way to synthesize the good properties of two alloys and improve the applicability of the correlative products.In this paper, diffusion bonding experiments were processed by adjusting the main technical parameters of diffusion bonding (bonding temperature, bonding pressure and bonding time). Fractograph of joints were detailedly analyzed. The influence regulation of each main technical parameter to the bonding quality was obtained. And the optimal technical parameters of the diffusion bonding were confirmed. Using SEM, XRD apparatus, the diffusion state of each main element, the sort and distribution in the interface, and the influence of the microcosmic organization to the bonding quality were observed and analyzed. The superplastic diffusion bonding of TC4 and 1Cr18Ni9Ti was investigated thoroughly and systematically.The research results show that: the optimal superplastic diffusion bonding technical parameters are the temperature of 760℃～790℃, the stress of 3～5Mpa, the time of 20～30min and the nickel thickness of 30nm. At those condition, the shear strength reached t=131.1MPa.Using nickel as interlayer, it can prevent diffusion between Ti, Fe and C, so the properties of the joint can be improved by avoiding more intermetallic compound. NiaTi, NiTi, NiTi₂ are detected in Ni-Ti interface.Using ultrasound waterlogging C-scanning imaging system can inspect the joint-rate state of superplastic diffusion bonding interface on dissimilar materials. Between the results and interface disfigurements distributing of practical measuring values have preferable consistency. In the optimal bonding technology conditions, the joint-rate of superplastic diffusion bonding between TC4 alloy and 1Cr18Ni9Ti stainless steel can arrive at 94%.According to the second law of Fick, the diffusion bonding concentration field of TC4/1Cr18Ni9Ti under a certain condition by Matlab was simulated in this paper. The results show that the simulative curves and the testing results have well consistency,...