高级检索

能量输入对微区熔凝铜钢双金属组织和性能的影响

Effects of heat input on microstructure and mechanical properties of copper/steel bimetal by microzone melting

  • 摘要: 采用微区熔凝在钢基板上熔覆锡青铜得到了铜钢双金属材料. 应用ANSYS软件研究了微区熔凝过程的基体温度变化和试样不同区域冷却速度变化. 应用光学显微镜(OM)、X射线衍射仪(XRD)、电子探针(EPMA)及显微硬度计等手段研究了试样不同区域锡青铜层的组织和性能差异. 结果表明,随着熔覆过程进行,基体温度由20 ℃升高到433 ℃,熔池冷却速度由2 070 K/s降低到336 K/s,堆焊层硬度由199 HV降低到137 HV,微区熔凝得到的锡青铜层开始时主要由αCu,Pb和αFe组成,结束时由αCu,Pb元素和分布在树枝晶间的富Sn相的δCu相构成;随着堆焊过程进行,αCu晶粒尺寸由外向里由11.2 μm增大到53.4 μm.

     

    Abstract: Copper/steel bimetal materials were obtained with cladding tin bronze on steel substrates by microzone melting. The changing of steels substrate temperature and microzone cooling velocity were simulated by ANSYS. Microstructure and mechanical properties of different region were investigated by optical microscopy(OM), X-ray diffraction(XRD), electron probe microanalysis(EPMA) and micro hardness tester. The results show that as the surfacing process went on, the temperature of the steels substrate increased obviously from 20 °C to 433 °C. The cooling speed decreased from 2 070 K/s to 336 K/s and the hardness of the surfacing layer decreased from 199 HV to 137 HV. The initial peripheral Tin-Bronze coating consisted of αCu, Pb and αFe, which were the product of the Cu-Fe liquid phase separation having a characteristic of metastable liquid phase separation. The grain size of αCu increased from 11.2 μm to 53.4 μm.

     

/

返回文章
返回