Preparation Of High Hardness Beryllium Bronze Die And Its Research On Microstructures Properties

Beryllium bronze is one kind of typical age-strengthening alloy for its good propertiessuch as high strength, high elasticity, high electrical conductivity，fatigue resistance，non-magnetism and so on. So, the application prospect of beryllium bronze is widely atpresent.In this paper, using vacuum induction melting (VIM) to reduce the content of gas,inclusions and harmful elements in Cu-Be-Co-Ti alloy, improve the organizational structureand uniformity of the alloy. And then beryllium bronze was prepared by hot forging→hotrolling→cold drawing→solid solution treatment→aging treatment. The mechanical andphysical properties promances were tested with using conductivity tester, Brinell hardnessmachine, universal testing machine and other equipments. The microstructure and facturesurface were tested with using optical microscopy, scanning electron microscopy, X-raydiffraction, transmission electron microscopy and other equipment. Analysis the relations ofthe alloy composition, microstructure and properties. Study the effect of the three factors onmechanical properties, electrical properties and organizational structure. Then make thetheoretical analysis.The results show that: It can receive the best mechanical and electrical properties whenthe Cu-Be-Co-Ti alloy through840℃×50min solution treatment(waterqueching)+300℃×2h aging treatment(furnace).In this time, the hardness was38HRC,tensile strength was1267Mpa, conductivity was21.89%IACS. The rich beryllium phaseswere solved enough in the α-substrate after solid solution treatment. The α-grain boundarybecomes widely precipitated phases that slightly aggregate on grain boundary were foundand elutriation linellaes in interior of α-grain evidently come forth after aging treatment.Fracture morphology of the Cu-Be-Co-Ti alloy was plastic fracture after280℃×2h agingtreatment, and was intergranular fracture after300℃×2h aging treatment, and was brittleintergranular fracture after320℃×2h aging treatment.The aging treatment, especially aging temperature is the important factor to electric conductivity. Aging treatment decreases the content of solution elements, so electricconductivity of Cu-Be-Co-Ti alloy is remarkably increased.