Research On The Metal Joining Technology And Performance Based On The Amorphous Interlayer

Finding a high-efficient and reliable connection technology is always a major research direction in the area of material science. The technique for obtaining amorphous solder injects a positive vigor to the traditional welding methods. In this paper, after the preparation of different amorphous interlayer, the author studied the weldability of these fillers among different metal-based materials connected by laser weld method. By studying the diffusion welding between titanium alloy and titanium-aluminum alloy connected by titanium-based amorphous interlayer, an amorphous interlayer diffusion processing method with relatively stable parameters was obtained.Several materials like iron-based, nickel-based and aluminum-based amorphous ribbons with high surface smoothness, good toughness and high amorphous formability were prepared by the single roller method. A series of experiments, concerning the connection between plain carbon steel and stainless steel plate using iron-based amorphous interlayer, different zirconium alloy plates using nickel-based amorphous filler, two pieces of7075aluminum plates using aluminum-based amorphous interlayer, were conducted in order to evaluate the metallurgical properties of these amorphous interlayer. The results showed that the bonding strength of all these connections was relatively high and met the requirements of the Project. Using DSC method combined with Ti-Al phase diagram, the heat treatment processing parameters of Ti47A12Nb2Cr and Ti45A18.5Nb alloys with fully lamellar structure were obtained, that was1355℃/30min/vacuum furnace cooling and1400℃/60min/vacuum furnace cooling, respectively. The experimental results about the joining strength by adding amorphous interlayer between Ti47A12Nb2Cr/Ti6A14V couple and Ti45A18.5Nb/Ti6A14V couple under the diffusion condition with the parameter as915℃/80MPa/1h showed that both diffusion couples exhibited good connecting conditions and were metallurgically connected.By comparison, it was found that the mechanical properties of joints could be enhanced by changing the microstructure of TiAl based alloy into fully lamellar structure through heat treatment. The tensile strength of Ti47A12Nb2Cr/Ti6A14V couple jointed by titanium-based amorphous interlayer is slightly higher than that of being jointed by nickel-based interlayer, and could reach85%tensile strength of the Ti6A14V alloy even at500℃. The experimental results also showed that the comprehensive mechanical properties of Ti45A18.5Nb/Ti6A14V couple jointed by adding double-decked titanium-based amorphous interlayer were better than that of being jointed by adding only one layer of such interlayer. The yield phenomenon could be observed for the couple jointed by two layers of interlayer with tensile strength about580.6MPa at500℃, which is90.4%of the tensile strength of couple materials.