The preparation method and processing process include billet preparation and plastic processing, welding, heat treatment and coating.
Niobium and hafnium alloy is usually prepared by the active method of electron beam melting and true blank arc consumption melting, and then the billet is extruded or forged under the temperature of 1200℃ or above, and rolled and drawn under the temperature of 500℃ or below.
Welding niobium and hafnium alloy has good weldability. Argon tungsten electrode welding and electron beam fusion welding are usually adopted to realize the connection of parent metal, and these two welding methods can also be used to complete the welding of niobium and hafnium alloy with titanium and titanium alloy. The quality of welding seam is related to argon purity and vacuum degree. Generally, the higher the purity of argon, the lower the residual atmospheric pressure, the better the quality of welding seam.
Heat treatment generally adopts vacuum or inert gas protection annealing treatment and solution aging treatment.
The coatings are usually cr-ti-si and cr-fe-si antioxidant coatings. The niobium and hafnium alloy coated with these two coatings has an antioxidant life of over 150h at 1371℃.
Mainly used in liquid rocket engine radiation cooling nozzle extension section and thrust chamber body, space power generation system molten sodium and sodium potassium alloy pressure pipe and turbine pump, high temperature structure parts of jet engine, etc.
