隨著科技文明的發展,工業上對複合工具鋼的要求日漸提高;就工具鋼而言,其本身具有較高的強度與韌性,在工具鋼內添加入一些硬質的碳化物如碳化鈦、碳化鎢、碳化釩、碳化鈮及碳化鉻等等,便可同時獲得具有工具鋼韌性與硬質碳化物的高硬度新材料。複合工具鋼經由粉末熱均壓製程後,可以製造出高合金化、高緻密性及化學均一性之產品,且具有細緻的晶粒結構和均向性的機械性質。本研究將碳化鈦粉分別加入高釩及高鉻工具鋼金屬粉混合封罐後,進行熱均壓處理,以孔隙率、硬度試驗、三點抗彎強度試驗、顯微組織觀察及腐蝕試驗進行分析,來探討熱均壓製程對於複合工具鋼強化的效果。由研究結果我們可得知,經由熱均壓處理後,不規則角狀碳化鈦的添加後可以讓燒結體達到99.9%以上之理論密度。碳化鈦也可使其硬度明顯增加,微幅提高燒結體之衝擊值。在腐蝕試驗中,對於H2SO4的腐蝕液,燒結體可形成鈍態膜,使得其對於H2SO4的抗腐蝕性較好,反之在FeCl3腐蝕液中,因為氯離子的作用,容易形成蝕洞之現象,所以對於FeCl3抗腐蝕效果最差。
Tool steels in tradition are characteristic of excellent rigidity and toughness. The addition of hard carbides such as TiC WC, VC, NbC, and Cr3C2, etc. can further improve their strength and toughness. The hot isostatic press (HIP) treatments are often applied to achieve higher densification and chemical homogeneity product. In this study, TiC powders are added to two different types of high vanadium tool steel powders for canning. The encapsulation is then HIPped for densification. The density and mechanical properties of these composite tool steels are characterized. Product densification of over 99.9% theoretical density was obtained. Its hardness has shown to increase effectively by TiC addition. The sintered bodies generate the passive layer which demonstrate best corrosion resistance in H2SO4 . In contrast, the sintered bodies form pits in the FeCl3 corrosive solution.