微合金化Cu-Ni-Sn-P合金的组织和性能

利用光学显微镜(OM)、扫描电镜(SEM)、透射电镜(TEM)、显微维氏硬度计和涡流电导率仪,分析了不同镍锡比对Cu-Ni-Sn-P合金铸态、固溶态及时效态组织和性能的影响,从而优化了Cu-Ni-Sn-P合金中镍和锡元素的成分配比,同时研究了不同形变热处理工艺对Cu-0.87Ni-1.82Sn-0.07P合金组织和性能的影响。结果表明,Ni∶Sn为1∶2时Cu-Ni-Sn-P合金(Cu-0.87Ni-1.82Sn-0.07P合金)的综合性能最佳,固溶时效处理后硬度最高达119.9 HV0.5,电导率为35.0%IACS。时效前经过30%预冷轧变形能提高时效峰值硬度,450 ℃时效后硬度可达164 HV0.5。断口组织多为韧窝,韧性较好,抗软化温度为480 ℃。时效强化析出相与位错为切过关系,析出相呈现为球形Ni-P颗粒;晶界处析出颗粒较大,晶内析出的颗粒普遍较小,尺寸介于几十纳米到数百纳米之间。

Microstructure and properties of microalloyed Cu-Ni-Sn-P alloy

Effect of different nickel-tin ratios on as-cast, solid-solution and aging microstructure and properties of Cu-Ni-Sn-P alloys was analyzed, so as to optimize the composition ratio of nickel and tin elements in Cu-Ni-Sn-P alloys by means of optical microscope (OM), scanning electron microscope (SEM), transmission electron microscope (TEM), micro Vickers hardness tester and eddy current conductivity meter. At the same time, effect of different deformation heat treatment processes on the microstructure and properties of Cu-0.87Ni-1.82Sn-0.07P alloy was studied. The results show that for the Cu-Ni-Sn-P alloys with different composition, the Cu-Ni-Sn-P alloy (Cu-0.87Ni-1.82Sn-0.07P alloy) has the best comprehensive properties when Ni∶Sn is 1∶2, the hardness after solution and aging treatment is up to 119.9 HV0.5, and the conductivity is 35.0%IACS. The peak aging hardness of the alloy can be increased up to 164 HV0.5 after 30% pre-cold rolling before aging at 450 ℃. The fracture structure is mostly dimples with good toughness and the anti-softening temperature is 480 ℃. There is a tangential relationship between the age-strengthened precipitated phase and dislocation, and the precipitated phase presents spherical Ni-P particles. The precipitated particles at grain boundary are larger, and the precipitated particles in grain are generally smaller with sizes ranging from tens to hundreds of nanometers.