( 1. 中南大學(xué) 粉末冶金國家重點(diǎn)實(shí)驗(yàn)室， 長沙 410083;
2. 株洲鉆石切削刀具股份有限公司， 株洲 412007)
摘 要: 用X射線衍射、 背散射掃描電鏡及能譜儀等分析手段研究了燒結(jié)氣氛(真空、 N2、 Ar)對不同成分TiC基和Ti(CN)基金屬陶瓷合金顯微組織和性能的影響。 金屬陶瓷在N2和Ar中燒結(jié)后， 合金碳含量比在真空中燒結(jié)的碳含量低0.5%左右； 在N2中燒結(jié)后， 合金的氮含量提高了0.5%左右。 環(huán)狀結(jié)構(gòu)心部可以是以鎢等重金屬元素為主要成分的碳化物， 也可以是以鈦為主要成分的碳化物和碳氮化物。 環(huán)狀結(jié)構(gòu)為金屬元素含量和分布不同的(Ti, W, Ta, Mo, Co, Ni)(C, N)固溶體， 粘結(jié)相是與Ti, W, Ta, Mo, C, N等元素有不同溶解度的鈷鎳固溶體。 真空燒結(jié)后組織結(jié)構(gòu)比較均勻， 合金的性能最好。 在Ar、 N2中燒結(jié)后， 氣氛中的氧和氮參加燒結(jié)反應(yīng)， 影響合金成分碳氮平衡， 在合金表面形成殼層結(jié)構(gòu)， 產(chǎn)生表面缺陷， 合金的密度、 顯微硬度、 抗彎強(qiáng)度均有比較大的降低； N2氣氛影響更大。
關(guān)鍵字: 金屬陶瓷; 燒結(jié)氣氛; 相成分; 微觀組織; 力學(xué)性能
（ 1. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China;
2. Zhuzhou Cemented Carbide Cutting Tools Co.LTD, Zhuzhou 412007, China）
Abstract: Effect of the sintering atmospheres (vacuum, N2, Ar) on the microstructures and properties of the TiC and Ti(CN) based cermets was studied by X-ray diffractrometry, scanning electron microscopy and energy spectrometer. Compared with the alloys sintered in vacuum, the carbon content of the cermets sintered in N2 and Ar is lower by 0.5%; and the nitrogen content is higher by 0.5% when sintered in nitrogen. The central part of the ring structure may be either carbide with a high W content or carbonitride with a high Ti content. The ring structures are (Ti, W, Ta, Mo, Co, Ni)(C, N) solid solutions with different metallic elements and distributions. The composition of the binder phase are (Co, Ni) solid solutions with different Ti, W, Ta, Mo, C, N contents. The structures are uniform for the cermets sintered in vacuum and the properties are the best. When sintered in Ar or N2, the O2 and N2 in the atmosphere take part in the sintering reaction to break the balance between the carbon and nitrogen in the cermets to form a shell structure and defects, which result in poor density, microhardness and transverse rupture strength.
Key words: cermets; sintering atmosphere; phase compositions; microstructure; mechanical properties
