Preparation Of High Strength Beryllium Bronze QBe2 Wire And Its Properties Study

Beryllium bronze(QBe2) is one kind of typical age-strengthening alloy and named "the king of Non ferrous elastic materials" due to its good properties such as high elasticity, high strength, electrical conductivity, corrosion resistance, fatigue resistance, non-magnetism and so on. Therefore, the application prospect of beryllium bronze is wide at present.QBe2 alloy wire was prepared by medium frequency fusion Casting-hot forging -hot rolling-cold drawing-solid solution treatment- Aging treatment. The effects of parameters of solid solution temperature, aging temperature, aging time and cold deformation before aging to alloying structure, alloying properties as well as aging characters were studied systematically by the mechanical property test, electrical performance test, optical microscopy and scanning electron microscopy, and theoretic ally analyzed the relevant mechanism.The result indicated that tensile strength of QBe2 alloy is 1257MPa when it was solid solution treated in 780℃×10min and Aging treated for 320℃×2h.The rich beryllium phases are solved enough in a- substrate after solid solution treatment. The a-grain boundary become wide, precipitated phases that slightly aggregate slightly on grain boundary are found and elutriation linellaes in interior of a- grain evidently come forth after aging treatment. Fracture morphology showed that QBe2 are plastic fracture because of many fine and uniform dimple distributing in fracture after solid solution treatment, and QBe2 are brittle intergranular fracture due to a large number of discontinuous hard and brittle phases appearing in grain boundary after aging treatment.After cold forming, aging treatment of QBe2 alloy is in favor of precipitating precipitated phases along glide line of intracrystalling and restraining grain boundary that precipitated phases appreciably aggregate in. Deformation aging treatment may improve precipitated velocity of QBe2 alloy. Peak time become shorter and strength of QBe2 alloy in initial stages of aging treatment increase quickly with cold forming of QBe2 alloy. By orthogonal test, optimum process is 44% Cold forming +300℃ ×2h aging treatment. Compared to the common peak value, QBe2 alloy strength, which is 1400MPa, increase 11% by this process.Aging treatment, especially aging temperature is important influencing factor to electrical resistivity. Aging treatment decrease the content of solution elements andreduce scattering reaction to the electrons, so electrical resistivity of QBe2 alloy is remarkably decreased. However, to QBe2 alloy was treated aging after deforming, electrical resistivity of QBe2 alloy decrease correspondingly quickly at early stage of aging and then slowly, thus deformation aging process not only markedly improve strength but also doesn't obviously decrease conductivity of QBe2 alloy.