Alloying of Stacked Single Films Through Heating for Making Chromium-free Hard Films

铬和镉对我们的环境非常有害。因此，它们的使用将在21世纪受到严格限制。镀铬在硬度、耐腐蚀性、美观性等方面表现出优异的性能。另一方面，由于镉镀层具有很高的耐腐蚀性，因此经常被使用。但是，由于环境友好性较低，两者都将被限制使用。因此，迫切需要建立它们的替代品。我们着眼于镍锡体系作为铬的替代品，通过加热每层厚度为10微米的锡和镍单层薄膜，成功地制备了锡和镍之间的金属间化合物薄膜。当我们将加热工艺从通常的炉内加热改为激光辐照后，合金薄膜的形成时间大大缩短。我们将该工艺应用于锡锌体系中代替镀镉，并成功地制备了合金膜。XRD和SEM-EDX分析结果表明，在加热过程中锡和锌发生了合金化。当加热工艺由传统的炉内加热改为激光辐照后，合金的工艺时间大大缩短。

Chromium and cadmium is very harmful for our environment. Therefore, their uses will be restricted strictly in the twenty first century. Chromium plating has shown it's high performances for hardness, corrosion resistance, and fanciness. On the other hand, cadmium plating has been often used due to it7s high corrosion resistance. However, both of them will be used restrictively due to the low environmental friendliness. Therefore, the establishment of their substitutes are required urgently. We focused on nickel-tin system as substitute for chromium and succeeded in making intermetallic compound films between tin and nickel by heating the stacked single films of tin and nickel where each layer had 10 micrometer thickness.When we changed the heating process from usual furnace heating to laser irradiation, the formation time required for making the alloy films was reduced drastically. We applied this process to tin-zinc system as substitute for cadmium plating and also succeeded in making the alloying film. XRD and SEM-EDX results suggest that alloying of tin and zinc occurred through heating process. When the heating process was changed from usual furnace heating to LASER irradiation, the process time require^ for the alloying was reduced drastically.