磁场作用对高速钢刀具表面磷化处理的影响及机理探讨

Effect and Mechanism of Magnetic Fields on Phosphate Treatment on High-speed Steel Tools

磁场对高速钢磷化过程的影响显著:促进成膜并促使膜的外貌和组成有很大改变。磷化反应的速度取决于整个反应系统的有序或无序状态,即取决于熵。外加磁场促使磷酸铁盐和磷酸氢铁盐有序排列,能够更快地沉积在金属表面上。即一定强度的磁场可以降低磷化处理系统的熵值,加速磷化盐膜的形成。因而磁场对磷化过程中磷化膜的成膜及外观、膜重等产生直接影响,有利于高速钢基底成膜,避免了使用硝酸盐或亚硝酸盐等磷化促进剂所造成的不利影响,其较佳的磁场强度为1.3×10-3T-3.8×10-3T。

Effect of external magnetic fields on phosphate treatment on high-speed steel is significant： promoting the building of phosphate film and greatly improving the appearance and composition of the film. The reaction speed of phosphate is decided by the state of order or disorder of the whole system, which is the entropy of the whole. External magnetic fields can make the particle of ferric phosphate and hydrogen phosphate motysite in order, which can rapidly deposit on the mental surface. That is, a certain intensity of magnetic field can reduce the entropy of the phosphate treatment system and accelerate the formation of phosphate film. So in the whole phosphate process, magnetic fields have a direct impact on the building, the appearance and the membrane of the phosphate film, which help to form phosphate film on substrate of the high-speed steel and avoid the adverse effect of using phos- phate accelerator such as nitrate or nitrite. Better magnetic field intensity is 1.3×10^-3T～3.8×10^-3T.