Cu—4%Ti合金胞状反应的研究

利用透射电子显微镜对Ｃｕ－Ｔｉ合金较低温度时效的胞状反应进行了研究．结果表明，低温时效胞状反应经历了调幅分解、有序化等过渡过程．过饱和固溶体先通过调幅机理分解为贫、富溶质区，然后富溶质区发生有序化，形成亚稳有序相Ｃｕ４Ｔｉ（Ｄｌａ型），最后发生胞状反应，亚稳有序相转变为同成分的斜方晶系平衡相，基体贫化为极稀浓度固溶体．低温时效胞状组织或者由调幅组织直接析出形成，或者通过调幅组织中亚稳相的粗化和平衡相的重组来形成，后者不同于经典的胞状反应．

An Investigation on Mechanism of ElectrolessNi P PTFE Co deposition

Effects of some factors on PTFE particles depositing in the course of electroless Ni P PTFE plating were investigated by measuring content and distribution of particles in coatings. The testing results show that the surfactant is a key factor for electroless Ni P PTFE co depositing. Surface condition of specimens and plating process also affect the behavior of co deposition. A co depositing mechanism of the composite coating was suggested: PTFE particles are captured by the surface of substrate with the aid of mechanical collision and electrostatic absorption, co depositing to the surface in company with Ni P.