本文關(guān)鍵詞： Al ON陶瓷 粉體合成 放電等離子燒結(jié) 致密化行為 抗氧化性能　出處：《哈爾濱工業(yè)大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：本文采用高溫固相反應(yīng)法和碳熱還原氮化法制備Al ON陶瓷粉體,利用放電等離子燒結(jié)(SPS)技術(shù)制備了Al ON陶瓷材料。研究了原料及配比和合成的工藝參數(shù)對(duì)Al ON陶瓷粉體合成產(chǎn)物的影響。并在此基礎(chǔ)上,研究了SPS燒結(jié)的工藝參數(shù)對(duì)其致密化過程及組織結(jié)構(gòu)和力學(xué)性能的影響。同時(shí)研究了其抗氧化性能。以α-Al2O3和Al N為原料,通過高溫固相反應(yīng)法成功制備出單相的Al ON陶瓷粉體。研究結(jié)果表明,在1700℃-1800℃溫度范圍內(nèi)固相反應(yīng)合成Al ON陶瓷粉體時(shí),較高的合成溫度(1800℃)有利于Al ON陶瓷粉體的合成;延長(zhǎng)保溫時(shí)間,可以提高Al ON陶瓷粉體的產(chǎn)率;α-Al2O3和Al N的摩爾比為73:27時(shí),1800℃保溫2h,制備出單相的Al ON陶瓷粉體。以γ-Al2O3和活性炭為原料先在0.5MPa氮?dú)鈼l件下1600℃保溫2小時(shí),然后升溫到1800℃保溫3h成功制備出單相Al ON陶瓷粉體。在1600℃保溫2h的產(chǎn)物中Al N的含量隨活性炭含量的增加而增加,當(dāng)活性炭含量超過6.0wt%時(shí),其產(chǎn)量不再增加。提高合成溫度和延長(zhǎng)保溫時(shí)間都能使產(chǎn)物中Al ON的含量增加。經(jīng)過球磨處理24h后,制備的Al ON粉體顆粒規(guī)則,近似于球形,粒徑細(xì)小且分布均勻。采用放電等離子燒結(jié)(SPS)技術(shù)快速制備出Al ON陶瓷材料。研究結(jié)果表明,相比于氮?dú)猸h(huán)境,真空環(huán)境下更有利于Al ON陶瓷的致密化;提高燒結(jié)溫度和升溫速率可以促進(jìn)其致密化,延長(zhǎng)保溫時(shí)間對(duì)其致密度影響不大,但會(huì)造成晶粒粗大,降低其彈性模量和抗彎強(qiáng)度,但是其斷裂韌性會(huì)增加。Al ON陶瓷在900℃-1200℃之間不同保溫時(shí)間下的抗氧化性能研究結(jié)果表明,隨著氧化溫度和時(shí)間的增加,其氧化增重及氧化層的厚度都增加。且隨著氧化溫度的提高,Al ON陶瓷的氧化反應(yīng)速率也增加;在1200℃以下,Al ON陶瓷具有很好的抗氧化性能,氧化的產(chǎn)物主要為γ-Al2O3。超過1200℃以后,Al ON陶瓷會(huì)產(chǎn)生嚴(yán)重的氧化,產(chǎn)物主要為α-Al2O3;其氧化過程分為三個(gè)階段,氧化初期為化學(xué)反應(yīng)控制階段;Al ON陶瓷的氧化中期是擴(kuò)散和化學(xué)反應(yīng)共同控制階段;氧化后期是擴(kuò)散控制階段。
[Abstract]:In this paper, Al on ceramic powders were prepared by high temperature solid state reaction and carbothermal reduction nitridation. Alon ceramic materials were prepared by spark plasma sintering (SPS) technique. The effects of raw materials, ratio and process parameters on the synthesis products of Alon ceramic powders were studied. The effects of sintering parameters of SPS on the densification process, microstructure and mechanical properties of SPS were studied, and the oxidation resistance was also studied. 偽 -Al _ 2O _ 3 and Al _ 2O _ 3 were used as raw materials. Single phase Al on ceramic powders were successfully prepared by high temperature solid state reaction. The results showed that Al on ceramic powders were synthesized by solid state reaction in the temperature range of 1700 鈩，

本文編號(hào)：1538885