發(fā)布時(shí)間：2018-03-09 01:33

  本文選題：氧化硅基陶瓷型芯　切入點(diǎn)：剛玉　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】：陶瓷型芯的研究對(duì)高溫空心葉片生產(chǎn)具有重要的參考價(jià)值。陶芯的綜合性能包括強(qiáng)度、高溫?fù)隙�、開氣孔率、收縮率等,缺一不可,本課題針對(duì)目前實(shí)際生產(chǎn)中大型復(fù)雜硅基陶瓷型芯高溫強(qiáng)度難以滿足要求等問題進(jìn)行研究。本文通過總結(jié)以往研究和應(yīng)用成果,通過大量實(shí)驗(yàn)確定了型芯基本成分;同時(shí)通過對(duì)型芯抗彎強(qiáng)度、高溫?fù)隙�、收縮率、開氣孔率等性能的測(cè)量,通過微觀組織觀察和燒結(jié)相組成分析,研究了剛玉礦化劑,方石英和Na OH等添加劑對(duì)硅基陶瓷型芯綜合性能的影響,最終得出較合理的陶瓷型芯成分和制造工藝參數(shù)。剛玉微粉的加入使陶芯室溫抗彎強(qiáng)度有很大的提高,添加5%200目剛玉微粉的陶芯抗彎強(qiáng)度達(dá)18.614 MPa,強(qiáng)度提高約7.4 MPa,收縮率為1.364%,1550℃條件下高撓度值為1.833mm,綜合性能良好。添加剛玉微粉的粒度配比需結(jié)合總體粉料的顆粒分布進(jìn)行考慮,當(dāng)添加剛玉微粉的含量為15%時(shí),200目:400目:600目配比5:3:2的陶芯綜合性能優(yōu)于未配比的陶芯。相較于1200℃,終燒溫度為1180℃陶芯性能較佳。方石英的加入對(duì)陶芯綜合性能的有一定的改善作用。預(yù)加一定量的方石英有利于改善陶芯收縮率和高溫性能,但加入量要合理控制。預(yù)加5%方石英用剛玉微粉陶芯的高溫性能良好,撓度值降低為0.816mm(1550℃持溫30min),收縮率降低0.306%,抗彎強(qiáng)度為14.162MPa。少量Na OH的加入對(duì)陶芯收縮性能影響明顯,添加0.5%Na OH的陶芯,由于Na+破壞Si-O和Al-O,添加剛玉微粉中得到的Al3+變?yōu)椴ＡЬW(wǎng)絡(luò)變性離子,促進(jìn)方石英的析出,使陶芯的收縮率減至0.45%,陶芯的尺寸精度良好,開氣孔率升為0.356,脫芯更容易,1550℃條件下高溫?fù)隙戎禐?.25mm(1550℃持溫30min),但Na+的引入量要嚴(yán)格控制,以保證良好的綜合性能。
[Abstract]:The study of ceramic core has important reference value for the production of high temperature hollow blade. The comprehensive properties of ceramic core include strength, high temperature deflection, open porosity, shrinkage, etc. In this paper, the current production of large and complex silicon-based ceramic core is difficult to meet the requirements of high temperature strength. This paper summarizes the previous research and application results, through a large number of experiments to determine the basic components of the core; At the same time, corundum mineralizers were studied by measuring the bending strength, deflection at high temperature, shrinkage and porosity of the core, observing the microstructure and analyzing the phase composition of sintered corundum. The effects of additives such as cristobalite and NaOH on the comprehensive properties of silicon-based ceramic cores were obtained, and the reasonable composition of ceramic cores and manufacturing process parameters were obtained. The flexural strength of ceramic cores at room temperature was greatly improved by the addition of corundum micropowder. The flexural strength of ceramic core added 50 mesh corundum micro-powder is 18.614 MPa, the strength is increased about 7.4 MPA, the shrinkage ratio is 1.36440 鈩，

本文編號(hào)：1586452