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新粉末渗铝技术通过在渗扩介质与被渗样品间施加合适参数的直流电场予以实现。分析了渗铝层显微组织及渗层厚度,测量了渗层硬度沿层深的分布及直流电场对温度场的影响,并进行了抗氧化性研究。研究结果表明:直流电场可降低外热温度,显著增加渗速;可将常规粉末渗铝温度900℃以上降低到700℃～750℃;外热温度为700℃～750℃时,通过施加合适的直流电场,渗铝层厚度可达到或超过180μm。直流电场不仅对试样有加热作用,而且在两极间形成温度差。新工艺处理的渗铝试样在850℃以下具有良好的抗氧化性能。
The new powder aluminizing technique is achieved by applying a suitable DC electric field between the infiltration medium and the infiltrated sample. The microstructure and the thickness of the aluminized layer were analyzed. The distribution of hardness along the layer depth and the influence of DC electric field on the temperature field were measured. The oxidation resistance was also studied. The results show that the DC electric field can reduce the external heating temperature and increase the infiltration rate obviously. The conventional aluminizing temperature can be reduced from 700 ℃ to 750 ℃ and the external temperature from 700 ℃ to 750 ℃, DC electric field, aluminized layer thickness can reach or exceed 180μm. DC field not only has a heating effect on the sample, but also the temperature difference between the two poles. The new process of aluminized samples below 850 ℃ has good oxidation resistance.