机械转动在机械能助渗铝技术中的作用

Action of rolling on mechanical energy aided aluminizing processes

机械能助渗铝技术是通过机械能与热能相结合,可以明显降低渗铝的温度与保温时间的一种先进工艺方法.研究结果表明:机械能助渗铝在600℃下保温3 h可以得到100μm以上的渗铝层;机械能助渗铝过程中由于滚筒持续的机械转动增加了渗铝剂与试样表面之间、渗剂内各组分之间的接触几率.颗粒与试样之间的摩擦能净化试样表面,增强表面活性,加快铝原子在试样表面的反应形核速率;由颗粒冲击而形成的大量晶体缺陷降低了扩散激活能,因此可以在较低温度下形成扩散层.

Combining heat and kinetic energy together,mechanical energy aided aluminizing processes can decrease heating tem-perature and reduce heating time.This technique could form a 100μm thickness aluminized layer on surface of steel samples only by treatment at 600℃for 180 min.Experimental results showed that rolling in the energy aided aluminizing increased the proba-bilities of contacts between the aluminizing agent and the sample surface,and between ingredients in the aluminizing agent.The friction between the grain and the sample could clean the surface of the samples,increase the surface activity,and accelerate the reaction and nucleation rate of Al atoms on the surface.The diffusion layers could be formed at a lower temperature due to the diffusion active energy decrease resulting from production of a great deal of crystal defects by shocking the grain agents.