(中南工業(yè)大學(xué)材料科學(xué)與工程系,長(zhǎng)沙 410083)
摘 要: 概述了Sialon陶瓷材料制備方面的研究。以高嶺土為主要原料 ,采用碳熱還原-氮化法合成的Sialon粉末為主要原料,分別添加Y2O3-Al2O3 系與Al 2O3-MgO系兩種燒結(jié)助劑后進(jìn)行充分混合,混合物粉末在鋼模中冷壓成兩種壓坯試樣a和b, 然后在N2氣氛中進(jìn)行無壓燒結(jié)。對(duì)燒成溫度與燒結(jié)體體積密度的關(guān)系,燒結(jié)助劑的作用以及Sialon粉末無壓燒結(jié)致密化過程進(jìn)行了重點(diǎn)討論。實(shí)驗(yàn)結(jié)果表明,分別添加10% Y2O3-5%Al2O3和10% Al2O3-5%MgO(均為質(zhì)量分?jǐn)?shù),%)兩種燒結(jié)助劑的試樣a 和b分別在1620 ℃和1590 ℃燒成溫度下,獲得了致密的Sialo n陶瓷材料。并且建立了Sialon粉末無壓燒結(jié)致密化模型,即lg(ΔV/V0)∝lg t,其致密化過程分為顆粒重排與溶解-析出兩個(gè)階段,且擴(kuò)散為全過程的控制性步驟。
關(guān)鍵字: Sialon粉末 燒結(jié)助劑 Sialon陶瓷材料
(Department of Materials Science and Engineering,
Central South University of Technology, Changsha 410083, P. R. China)
Abstract:The development of technology on sialon ceramic materials was reviewed.The samples made from the mixtures of proper additives, such as Y2 O3-Al2O3 and Al2O3-MgO, and sialon powder prepared from Kaolin through the carbothermal reduct ion and nitridation process have been sintered under N2 atmosphere.Relationship between volume density of samples and sintering temperature, effects of sintering additives and the densification procedure of pressless sintering of sialon powder were investigated. The results showed that the densified sialon ceramic materials could be obtained , when 10%Y2O3+5% Al2O3 and 10%Al2O3+5%MgO(all in mass fraction) were added in the mixtures respectively, under N2 atmosphere, soaking4h at 1620℃ and 1590 ℃ respectively. Besides, the densification mode of pressless sintering of sialon powder was established that was lg(ΔV/V0)∝lg t, of which densification procedure included grains reconstruction and dissolution-precipitation, and the diffusion is the crucial step during the whole densification procedure.
Key words: sialon powder sintering additive sialon ceramic materials


