本文選題：鈦基復(fù)合材料 + 包套熱擠壓��； 參考：《哈爾濱工業(yè)大學(xué)》2015年碩士論文

【摘要】：Ti B陶瓷增強(qiáng)鈦基復(fù)合材料因其優(yōu)異的耐磨性、耐腐蝕性及高的比強(qiáng)度等優(yōu)點,在航空航天及軍工領(lǐng)域有著廣闊的應(yīng)用前景。目前主要通過真空熱壓燒結(jié)、熱等靜壓等工藝實現(xiàn),但因其工藝復(fù)雜、設(shè)備昂貴、效率低下,極大地限制了其規(guī)�；瘧�(yīng)用。本文基于前期研究,提出了“高溫短時預(yù)燒結(jié)+包套熱擠壓”工藝,實現(xiàn)了對Ti Bw/Ti-6Al-4V復(fù)合材料棒材制備工藝的進(jìn)一步優(yōu)化,成功獲得組織致密、塑性良好復(fù)合材料棒材,并深入研究了擠壓溫度對其組織性能影響,同時探索了B元素對于Ti-6Al-4V基體組織的影響。采用“高溫短時預(yù)燒結(jié)+包套熱擠壓”工藝,成功制備出了Φ12×220mm的Ti Bw/Ti-6Al-4V復(fù)合材料棒材。1200℃短時預(yù)燒結(jié)可加速原位反應(yīng)進(jìn)行、明顯提升材料致密度,使鈦基復(fù)合材料棒材的生產(chǎn)效率大幅提升。工藝改進(jìn)后材料的室溫塑性提升明顯,當(dāng)擠壓溫度為950℃和1150℃時,復(fù)合材料的伸長率分別為5.08%和7.83%,達(dá)到了伸長率5%的預(yù)期目標(biāo)。深入研究擠壓溫度950℃~1150℃對Ti Bw/Ti-6Al-4V復(fù)合材料棒材組織性能影響。隨溫度升高,復(fù)合材料內(nèi)Ti B晶須數(shù)量逐漸下降,長徑比明顯提升;基體伸長型α相逐漸轉(zhuǎn)變?yōu)棣良途Ы绂料?并且基體中β相的數(shù)量也有所增加。當(dāng)擠壓溫度為950℃時,基體中表現(xiàn)出了較強(qiáng)烈的1010織構(gòu),此時材料的室溫抗拉強(qiáng)度達(dá)到1171.8MPa。當(dāng)擠壓溫度為1050℃時,基體α相表現(xiàn)出了強(qiáng)烈的0001和1010織構(gòu),此時的抗拉強(qiáng)度為1191.2MPa。當(dāng)擠壓溫度為1150℃時,基體中α相表現(xiàn)出了0001和1011織構(gòu),這時材料的抗拉強(qiáng)度達(dá)到1156.3MPa。三種材料的延伸率分別為5.08%、2.32%、7.83%。對比分析Ti-6Al-4V合金發(fā)現(xiàn):B元素使得基體中α相明顯細(xì)化,并且在Ti B晶須附近基體的α片層球化現(xiàn)象更加明顯。當(dāng)擠壓溫度為950℃時,材料塑性變形處于(α+β)雙相區(qū),B元素的存在顯著提升了Ti Bw/Ti-6Al-4V復(fù)合材料基體的β轉(zhuǎn)變溫度,使得基體中初生α相的1010織構(gòu)強(qiáng)度更高。并且大幅提升了Ti-6Al-4V基體的室溫拉伸性能。
[Abstract]:Due to its excellent wear resistance, corrosion resistance and high specific strength, TiB ceramic reinforced titanium matrix composites have a wide application prospect in aerospace and military industry. At present, it is mainly realized by vacuum hot pressing sintering and hot isostatic pressing, but because of its complex process, expensive equipment and low efficiency, its application on a large scale is greatly limited. In this paper, based on the previous research, the "hot extrusion process of high temperature and short time pre-sintering ladle shell" is proposed, which realizes the further optimization of the preparation process of Ti BW / Ti-6Al-4V composite rod, and obtains the compact microstructure and good plasticity of the composite rod successfully. The effect of extrusion temperature on the microstructure and properties of Ti-6Al-4V matrix was studied, and the effect of B element on the microstructure of Ti-6Al-4V matrix was investigated. By means of "hot extrusion of high temperature short-time pre-sintered ladle", Ti BW / Ti-6Al-4V composite bar with 桅 12 脳 220mm has been prepared successfully. Short-time pre-sintering at 1200 鈩，

本文編號：2018182