Processing technology of niobium alloy wire. It is characterized by the following steps: (1) bar billet rotary forging: the niobium alloy ingot is extruded or forged to obtain the diameter of the bar billet, and processed to the diameter of mm line billet after multiple passes of rotary forging and heat treatment; (2) oxidation coating on the surface; (3) Wire drawing: the diameter of the wire blank will be drawn for several times and two times of heat treatment to get the diameter.
The high temperature mechanical properties of niobium alloy were significantly improved by adding tungsten, molybdenum, zirconium and other high melting point metal elements into niobium matrix through typical strengthening methods of solution strengthening and precipitation strengthening. The tensile strength of niobium alloy reached 190MPa at 1400°C, which was nearly 4 times higher than that of C103 alloy. With a tensile strength of more than 70MPa at 1600°C and over 50MPa at 1800°C, the new niobium alloy improves the operating temperature of aerospace heat-resistant structural materials by more than 200°C.
Existing materials cannot be used at 1500° C and higher operating temperatures. The new high temperature and high specific strength niobium alloy (raw material group is divided into Nb-5Mo- 2Zr-LC, grade Nb521) rod billet is processed by rotary forging, surface coating and drawing, combined with appropriate heat treatment process and pickling oil removal process. The screw sleeve blank, diameter φ(λ5-(p:4.0mm, is used in high temperature special environment such as rocket and missile attitude control and orbit control engine material. The Nb521 alloy rod blank is obtained by rotary forging process with diameter φ2.0-(p6.0mm) line blank; The finished wire with bright surface and high dimensional precision was obtained by surface coating and drawing.
The main advantages are as follows: the processing properties of Nb521 alloy with high toughness and low plasticity can be fully developed by using the three-way compressive stress state of rotary forging processing; Through the appropriate heat treatment process, to eliminate the internal stress of the material, restore the shape, in order to realize the purpose of continuous processing; After heat treatment, the surface of the wire blank is coated with film, and a layer of isolation film is formed between the surface of the wire blank and the drawing die hole, so as to avoid the appearance of the membrane on the surface of the wire which affects the drawing process. The finished wire with high dimensional precision and bright surface can be made by drawing process.
