Study of solid-state sintered ?ne-grained cemented carbides
Submicron cemented carbides are most often produced by liquid phase sintering. To retard the grain growth during sintering,these materials are sintered at low temperatures and with addition of grain growth inhibitors, e.g. Cr and V. The common hypoth-esis is that the sintered material would bene?t from a more evenly distributed inhibitor in the WC raw material, in order to controlthe grain growth during both the solid-state and liquid phase part of the sintering.Aiming to study the distribution of Cr speci?cally after solid-state sintering, a Cr-doped WC-powder was mixed with Co andexcess of carbon, and subsequently hot-pressed for 1 h and 30 MPa at 1200 C. This transmission electron microscopy study showsthat Cr is concentrated to the surfaces of the WC grains in the sample after mentioned solid-state sintering.

納米硬質(zhì)合金是通常是通過液相燒結(jié)生產(chǎn)。為了延緩燒結(jié)中的晶粒生長(zhǎng)，通常在較低的溫度和添加晶粒生長(zhǎng)抑制劑的燒結(jié)，例如鉻和釩。為了控制在固液相燒結(jié)過程中的晶粒生長(zhǎng)，前提是在碳化鎢原料中的均勻分布的抑制劑有利于燒結(jié)材料。為了研究固相燒結(jié)后鉻的分布，含鉻碳化鎢粉和鈷和過量的碳均勻混合，隨后在1200℃, 30MPa熱壓下1 h。透射電子顯微鏡的研究表明鉻是集中在固相燒結(jié)后的碳化鎢晶粒表面。