Research On Processing Technology Of Copper Alloy Strip Without Beryllium With High Elasticity And High Electrical Conductivity

As the development for electronic components tending to be miniaturization,precision and high-performance, there are urgent needs for the materials which havehigh elasticity and high electrical conductivity. At present, the main elastic copperalloys including the beryllium bronze, the German silver, the titanium bronze, thealuminum bronze, the beryllium bronze and so on have been used as electricalconduction elasticity materials. Especially, the beryllium bronze has been widely usedin the fields of electronics, aerospace, instruments and meters and householdappliances due to its high elasticity as well as high strength, hardness, wear resistance,electrical conductivity and low stress relaxation characteristic. Though the berylliumbronze has excellent performance, but it is also expensive and poisonous withcomplicated processing routes. Therefore, the alternative materials of beryllium bronzeare one of the research hot topics at home and abroad. And a great progress has beenmade to the alternative material to high strength beryllium bronze, but a few studiesare focused on the alternative material to the high conductive beryllium bronze.In this paper, based on the research and development of a series of CuNiSi alloys,the LE702alloy was optimized as the alternative material to the high conductiveberyllium bronze by means of microalloying design with adding Zn and Mg alloyelements and researches on the solid solution-deformation heat treatment process.Combination the tests of pre-production line and large scale production line, it wassystematically and profoundly researched on the production process by means ofmechanical properties determination, optical metallographic analysis and thermalsimulation test in laboratory and pre-production test. The effects of smelting andprocess on the alloy performance were carried out. And the qualified samples wereproduced.In this paper, there are several innovative results are as follows. Firstly, the appropriate furnace lining material is optimized based on the research on the meltingloss rules of the LE702alloy melting in different furnace material. The additionsequence and time control of alloy elements are concluded. Secondly, the optimumhot-working temperature of750⁹50℃is determined based on the thermal simulationtest and the hot rolling temperature decrease simulation test. The beginningprecipitation temperature of the strengthening phase is about700⁷50℃. Thirdly, thecontradictions between product performance and specification contradiction wereresolved by means of multi-deformation heat treatments. Thus the excellentcomprehensive properties of the LE702alloy can be obtained.The results show that the performance of the LE702strip on industrialized productline can be achieved that the elastic modulus is1.25×10⁵MPa, the thermal expansioncoefficient is1.7×10^-5/℃,the tensile strength is725MPa, the yield strength is650MPa, the elongation is4.5%, the hardness is203HV and the electrical conductivityis53.1%IACS. It is fully meet or even exceeded the performance of QBe0.6-2.5alloy.