新型Cu-Sn-Ti-B合金线的组织与性能

采用水平连铸+冷轧+拉拔工艺试制了一种新型的Cu-Sn-Ti-B铜合金线,利用光学显微镜(OM)、扫描电镜(SEM),显微硬度测试、电导率测试和拉伸性能测试等手段,综合分析了水平铸造工艺、形变加工、等温热处理对合金微观组织以及性能的影响。结果表明,其组织为长度达到mm级的α相晶粒,冷加工后晶粒发生扭曲变形且被明显拉长;引杆速度在230mm·min^-1时合金铸杆抗拉强度达到186MPa,伸长率达到44%。对冷轧并拉成φ3mm的合金进行400～500℃等温退火100min,可发生再结晶,细化晶粒尺寸;不同温度等温退火后发现,在450℃等温退火100min后合金线的电导率达到48.314MS/m;在500℃等温退火100min后φ3mm合金线拉制成φ1mm时有最佳的综合性能,强度达到550MPa,电导率为47.56MS/m。

Microstructure and Properties of New Cu-Sn-Ti-B Alloy Wire

A new type of Cu-Sn-Ti-B alloy wire was designed by horizontal continuous casting-cold rolling and drawing.The effects of cold deformation and isothermal annealing on microstructure and properties of the alloy prepared were investigated by means of optical microscopy,scanning electron microscopy,hardness testing,electrical conductivity and tensile testing.The results show that the microstructure of the as-cast alloy is large bulkyαmatrix phase with a length of millimeters,after the cold working,the distortion of the crystal grains is obviously elongated.When the lead speed is 230 mm·min^-1,the as-cast alloy rod presents the desirable mechanical properties,where tensile strength and elongation reach 186 MPa and 44%,respectively.In addition,the alloy wire withφ3 mm is subjected to isothermal annealing at 400~500℃for 100 min,resulting in recrystallization in the alloy and refinement of the grains.After isothermal annealing for the alloy at different temperatures,it is found that a certain precipitation behavior can be observed in solid solution of the alloy.Meanwhile,after annealing at 400~500℃for 100 min,the alloy wire has a maximum electrical conductivity of 48.314 MS/m.The Cu-Sn-Ti-B alloy wire with a diameter of 1 mm has excellent performance with strength of 550 MPa and conductivity of 47.56 MS/m,which was drawn by the alloy wire withφ3 mm annealed at 500℃for 100 min.