我们在教学、科研中,常碰到钛合金材料的热成形和超塑成形问题。这两种情况下均需采用耐高温(700～900℃)材料模具,如K_3、K_5、耐热钢和中硅钼耐热球墨铸铁模具等。但这些材料高温硬度高、韧性大,用普通硬质合金刀具加工时易粘刀,易产生切屑瘤,刀刃磨损也很快。因此,我们选用了上海电器陶瓷厂生产的HP热压氮化硅材料制刀具。近两年来的实践表明:氮化硅是一种适于加工难加工材料的优良刀具材质,值得广泛推广。一、氮化硅刀具材料氮化硅是一种利用自然界中的氮(N)和硅 In teaching and scientific research, we often encounter the thermoforming and superplastic forming of titanium alloy materials. In both cases are required to use high temperature (700 ~ 900 ℃) material molds, such as K_3, K_5, heat-resistant steel and heat-resistant ductile iron mold and so on. However, these materials high temperature high hardness, toughness, easy to stick with ordinary carbide cutting tools, easy to produce chip tumors, blade wear quickly. Therefore, we chose HP hot-pressed silicon nitride tool made by Shanghai Electric Ceramics Factory. Practice over the past two years shows that silicon nitride is an excellent tool material suitable for machining difficult-to-machine materials and is worthy of widespread promotion. First, the silicon nitride tool material Silicon nitride is a use of natural nitrogen (N) and silicon