Experimental Studies on Improvement of Surface Properties of Material By Pulsed-Ion-Beam Implantation

传统的稳态带电离子束在焊接、半导体加工和光刻等材料的研发中得到了广泛而成功的应用。另一方面，强脉冲离子束(Lib)与传统的离子束有很大的不同，近年来被认为具有广泛的应用前景，特别是在材料科学方面。如果LiB被照射到材料上，表面将被迅速加热以产生高密度等离子体。在本实验中，我们对强脉冲Lib在材料科学中的应用进行了实验研究，其中Lib既被用作有效的“热源”，也被用作离子注入源。目前使用烧结BN或烧结磷灰石片作为离子源。研究：用不同的物理分析产品检查照射的效果。并对其硬度和辐照后的表面轮廓进行了研究。除了LiB照射外。为了考察材料的表面改性效果，还考察了氮气气流作用下的化学反应。得到的结论如下：(1)在有限的辐照条件下，获得了实质性的辐照效果。根据ESCA分析，植入的量很少，材料测试结果没有显示出明显的力学性能变化。(2)在上述温度下，氮气与钛板表层的化学反应非常活跃。1173K，氮气分压大于10^~(-2)；Torr。拉伸试验表明，与未处理的试件相比，0.2%的抗拉应力和抗拉强度提高了约10%。X-RNY分析没有观察到韧性的退化，并检测到了高度氮化物的存在。

Conventional, steady state charged ion beams have been widely and successfully applied in the R and D of materials such as in welding, semiconductor processing and lithography. On the other hand, intense pulsed light ion beam(LIB), which significantly differs from the conventional ion beams have been recently considered for various applications, particularly in material science. If the LIB is irradiated onto the materials, the surface will be quickly heated to produce high density plasma. In the present experiment, an intense pulsed LIB applications in material science have been experimentally studied, where the LIB is utilized as effective "heat" source as well as ion implantation source. Sintered BN, or sintered apatite chips were used as ion sorces of the present. study.The effect of irradiations were examined by various physical analysis procredures. The hardness and irradiated surface contours were also investigated. Besides the LIB irradiation. chemical reaction by nitrogen gas flow was also examined in order to investigate the surface modification effect of the materials.The obtained conclusions can be summarized as follows ;(1) The substantial effects of irradiation were obtained under the restricted irradiation conditions. According to analysis by ESCA, the amount of implantations were so small as the material test result showed no marked change of mechanical properties.(2) Chemical reactions of nitogren gas with the surface layer of titanium plate were so active under the temperatures above. 1173 K and nitogen partial pressure over 10^<-2> Torr. According to the tensile test, 0.2% proof stress and tensile strength increased by about 10% as compared to those specimens without treatment. No regression of the toughness was observed and an existence of high degree of nitrides were detected by X-rny annlysis.