Rapid Nitriding of Aluminum Using Nitrogen Glow Plasma

使用氮气r.f.辉光等离子体结果总结如下：由铝粉形成的球团在1000 ℃下快速氮化10分钟，转化率为94%。最佳的射频板功率。氮化铝纤维直径为1 μ m，直径为1.85kW。致密地堆积在氮化样品中。这种氮化可能是由活性氮物种N、N^+和N_2^+引起的，因为这样的快速低温氮化还没有报道。此外，还对颗粒（φ 6.2mm × 5.5mm）、板状（0.5 × 10.0 × 10.0mm）、立方体（10.0 × 10.0 × 4.0mm）和直径2 mm的颗粒进行了快速低温氮化处理。在Ar或Ar/H_2等离子体中没有观察到这种效应。采用H_2等离子体对铝板进行预处理，转化率可达97%以上。当使用由雾化粉末制备的粒料时，清楚地观察到反应过程。在这种情况下，通过氮辉光等离子体的氮化在铝块体的表面上进行。在界面处的铝通过反应热蒸发以与活化的氮反应，在表面上沉积AlN枝晶。内部的铝移动到边界，在样品底部形成洞穴。

The bulk of aluminum was rapidly nitrided using nitrogen r.f. glow plasma. The results were summarized below.A pellet formed from aluminum powder was rapidly nitrided at 1000ﾟC for 10min with a conversion of 94%. The optimum plate power of r.f. source was 1.85kW.Aluminum nitride fibers with 1mum in dia. were densely packed in the nitrided sample. This nitriding may be caused by activated nitrogen species N, N^+ and N_2^+, because such rapid and low-temperature nitriding has not been reported. Furthermore, the rapid and low-temperature nitridings were also achieved in the aluminums with other shapes ; grain(phi6.2mm*5.5mm), plate(0.5*10.0*10.0mm, cube(l0.0*l0.0*4.0mm) and grains with 2mm in dia.Pretreatment was done by Ar or H_2 plasma. The effect was not recognized in Ar or Ar/H_2 plasma. However, when H_2 plasma was used for the pretreatment of Al plate, the conversion of Al plate was increased to 97%.Furthermore, the nitriding process was studied by the interruption of the reaction. When the pellets prepared from atomized powder were used, the reaction process was clearly observed. In this case, the nitriding by the nitrogen glow plasma proceeds on the surface of the aluminum bulk. The aluminum at the boundary is evaporated by the reaction heat to react with the activated nitrogen, depositing A1N dendrites on the surface. The aluminum inside moves to the boundary to make a cave at the bottom of the sample.