Titanium alloy fasteners used in U.S. f-22 aircraft include: high-strength titanium alloy bolts, ring groove nails, smooth rod high-taper lock bolts, self-clamping bolts, titanium niobium rivets and bonding nuts. The C919, China's first domestically produced commercial large aircraft to fly in 2014, used more than 200,000 pieces of titanium alloy fasteners alone. The development and application of titanium alloy fasteners provide the possibility for further weight reduction of aircraft structure. Boeing 747 aircraft fasteners with titanium instead of steel, its structural weight reduced 1,814 kilograms. The Russian il-96 aircraft used 142,000 fasteners and lost 600 kilograms in titanium instead of steel.
Titanium alloy has excellent corrosion resistance, its positive potential and carbon fiber composite materials match, can effectively prevent the potential corrosion of fasteners.Ti45Nb alloy is a rivet material widely used in the aerospace industry in the United States. It has good tensile properties and shear strength when annealed. It can replace pure titanium rivet.Ti45Nb material also has a high plasticity, suitable for composite materials for the manufacture of joint rivets.
In recent years, Timeta1555 titanium alloy high-strength bolt developed by American aluminum company has the tensile strength of more than 1300MPa after solid solution aging, the double shear strength of more than 745MPa, and the elongation of more than 10%.In order to keep up with the development trend of international high-end titanium alloy fasteners, xitu super crystal company and xinyang aerospace standard parts factory jointly developed TB8 titanium alloy rod wire material for fasteners, and the tensile strength of the bolts made with it is up to 1280MPa.The research and development of titanium alloy fasteners is a very complicated and long-term work.
