本文選題：陶瓷基復(fù)合材料 + SrSO_4�。� 參考：《哈爾濱工業(yè)大學(xué)》2015年碩士論文

【摘要】：本文用化學(xué)沉淀法制備了不同顆粒尺度、微觀形貌的SrSO_4納米粉體。選用具有耐磨損、耐高溫和良好力學(xué)性能的Zr O2(3mol.%Y2O3)-20wt.%Al2O3(TZ3Y20A)作為基體材料,試驗制備的SrSO_4納米粉體作為固體潤滑劑添加到TZ3Y20A粉體中,放電等離子燒結(jié)出TZ3Y20A-SrSO_4陶瓷基自潤滑復(fù)合材料。試驗利用SEM、XRD、Raman、維氏硬度儀、密度天平、高溫摩擦磨損試驗機(jī)等測試手段觀察了SrSO_4粉體形貌,探究其生長機(jī)制,研究了TZ3Y20A-SrSO_4復(fù)合材料的組織結(jié)構(gòu)、力學(xué)性能以及摩擦學(xué)性能。改變試驗中的Sr~(2+)與SO_42-濃度比能得到不同形貌、粒度的SrSO_4。Sr~(2+)與SO_42-濃度比較低時制備出棒狀的SrSO_4粉體,其顆粒的平均粒度為長約250 nm,寬約100 nm,隨著Sr~(2+)與SO_42-濃度比增加,能夠制備片狀的SrSO_4粉體,其顆粒的平均粒度為長約350 nm,寬約300 nm。TZ3Y20A-SrSO_4復(fù)合材料燒結(jié)后物相主要由t-Zr O2、α-Al2O3及SrSO_4構(gòu)成。SrSO_4在復(fù)合材料中的含量不斷增大,材料整體的致密度、硬度都不斷增大。TZ3Y20A測試溫度由室溫至600℃升高,平均摩擦系數(shù)、磨損率隨之增大。數(shù)值曲線的波動越來越劇烈,波動的幅度也越來越大。TZ3Y20A室溫下,平均摩擦系數(shù)、磨損率分別為0.42、9.2 10-6 mm3/N m,在600℃時,平均摩擦系數(shù)0.91,磨損率為3.6 10-5 mm3/Nm。而對添加棒狀SrSO_4的TZ3Y20A-50wt.%SrSO_4復(fù)合材料,隨著測試環(huán)境溫度的升高,平均摩擦系數(shù)、磨損率均是先增大后減小,都是在200℃時最高,600℃時最低,在600℃下的平均摩擦系數(shù)為0.22,磨損率為0.03 10-5 mm3/N m,對添加片狀SrSO_4的TZ3Y20A-50wt.%SrSO_4復(fù)合材料摩擦系數(shù)、磨損率隨著測試環(huán)境溫度的升高,同樣是在200℃時最高,600℃時最低,600℃下摩擦系數(shù)、磨損率則為0.26、0.2 10-5 mm3/N m。TZ3Y20A-SrSO_4復(fù)合材料具有明顯優(yōu)于基體陶瓷材料的摩擦學(xué)性能,隨著SrSO_4含量不斷增加,復(fù)合材料摩擦系數(shù)和磨損率都有所降低,摩擦性能得到改善。棒狀的SrSO_4與片狀的SrSO_4相比,因其顆粒尺度較小,有利于燒結(jié)的致密化,所以添加棒狀SrSO_4粉體制備的復(fù)合材料有更高的致密度以及維氏硬度。在磨損過程中,添加棒狀SrSO_4復(fù)合材料形成更為均勻、平整、致密的表面潤滑膜,從而得到更低的摩擦系數(shù)和磨損率,表現(xiàn)出了更加優(yōu)異的摩擦磨損性能。SrSO_4具有塑性變形能力,測試溫度升高,SrSO_4的塑性變形能力變強,SrSO_4在磨損表面富集。受到摩擦剪切力和壓應(yīng)力的作用,富集的SrSO_4平鋪在磨損表面,逐漸形成一層致密、均勻、光滑的自潤滑膜在摩擦磨損過程中表現(xiàn)出了減磨潤滑的作用,整體提高了材料的摩擦磨損性能。
[Abstract]:In this paper, SrSOs _ 4 nanocrystalline powders with different particle size and micromorphology were prepared by chemical precipitation method. ZR O _ 2 O _ 2 O _ (2) O _ (3) mol.and Y _ 2O _ (3) -20wt.Al _ 2O _ (3) Al _ (3) O _ (3) Y _ (20) A) were used as matrix materials. The SrSO4 nano-powders were added as solid lubricant to TZ3Y20A powder, and TZ3Y20A-SrSO4 ceramic self-lubricating composites were sintered by spark plasma. The morphology of SrSO4 powder was observed by means of SEMXRDX Raman, Vickers hardness tester, density balance and high temperature friction and wear tester. The growth mechanism of SrSO4 powder was investigated. The microstructure, mechanical properties and tribological properties of TZ3Y20A-SrSO4 composite were studied. Different morphologies can be obtained by changing the concentration ratio of SrLi _ 2 to so _ 42-. SrSO4. SrSO42-) and so _ 42- are used to prepare the rod-like SrSO4 powder. The average particle size is about 250nm in length and 100nm in width, with the increase of SrSO2) and SO42- concentration ratio, the average particle size of SrSO4 powder is about 250 nm and 100 nm, with the increase of SrSO2) and SO42- concentration ratio, the average particle size of SrSSO4 powder is about 250 nm in length and 100 nm in width. The average particle size of SrSO4 powder is about 350nm in length and 300nm.TZ3Y20A-SrSO4 composite is about 300nm.TZ3Y20A-SrSO4 composite. The phase after sintering is mainly composed of t-Zr O _ 2, 偽 -Al _ 2O _ 3 and SrSO _ 4. The content of SrSO4 in the composite is increasing, and the density of the whole material is obtained. The hardness of TZ3Y20A increases from room temperature to 600 鈩，

本文編號：2048092