Synthesis of Composite Material by Laser Chemical Reaction

研究了以石墨、硼和钛粉为原料，反应激光烧结碳化硼(B_4C)和硼化钛(TiB_2)复相陶瓷。碳化硼是一种硬质材料，因此有望用作抛光粉。然而，碳化硼韧性较低，没有得到充分的利用。为了提高陶瓷的韧性，研制了碳化硼和硼化钛复合陶瓷。但这些材料(碳化硼和硼化钛)的硬度很高，很难压实。由于石墨、硼和钛粉的混合物硬度不高，采用目前的方法压制变得容易。首先，研究了制备复合陶瓷的条件。这种混合物是用激光照射的。用X射线衍射仪对材料进行分析，然后在碳化钛衬底上涂布硼粉，用激光扫描衬底。烧结层用作刀具。烧结层的刀具寿命与碳化钛刀具相同。

This research work deals with reactive Laser sintering of composite ceramics made of boron carbide (B_4C) and titanium boride (TiB_2) from the mixture of graphite, boron and titanium powder. Boron carbide is a hard material, therefore, it is expected to apply for polishing powder. However, boron carbide has low toughness, it is not used sufficiently. It is developed to produce composite ceramics made of boron carbide and titanium boride in order to improve the toughness of the ceramics. But it is difficult to compact these materials (boron carbide and titanium boride) because the hardness of the materials are very high. The compaction becomes easy by using present method because the hardness of the mixture (graphite, boron and titanium powder) is not high.At first, the conditions to produce the composite ceramics are examined. The mixture is irradiated by the YAG Laser beam. And the produced material is analyzed by X-ray diffraction.Next, boron powder is spread on the titanium carbide substrate, and the YAG Laser beam is scanning on the substrate. The sintered layer is used as a cutting tool. The tool life of the sintered layer is as same as that of the titanium carbide tool.