本文關(guān)鍵詞： 藍(lán)寶石 Al-12Si 超聲 潤濕 剪切強(qiáng)度　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】：藍(lán)寶石單晶具備高強(qiáng)度、高硬度、耐磨損、耐腐蝕、耐高溫、導(dǎo)熱性良好及光透過率高等特性,因此在微電子、光電行業(yè)、半導(dǎo)體、航空航天等工業(yè)上常作為襯底材料或窗口材料。但由于大尺寸藍(lán)寶石一次成型的難度較大,其本身具備的塑性較差,因而藍(lán)寶石在大尺寸構(gòu)件及形狀要求復(fù)雜的領(lǐng)域上的應(yīng)用受到了限制。解決此問題的方法之一就是采用焊接與連接的方法將小尺寸的藍(lán)寶石連接起來,根據(jù)需求制成不同形狀的藍(lán)寶石連接件�；诖�,本文以藍(lán)寶石單晶作為研究對象,提出在大氣環(huán)境下能有效快速成形的超聲波輔助釬焊方法,通過自行搭建的簡易超聲連接平臺(tái),系統(tǒng)的研究了超聲輔助釬焊藍(lán)寶石的可行性、不同超聲工藝參數(shù)對接頭性能的影響規(guī)律、超聲對焊縫組織的作用機(jī)理以及接頭組織形貌的演變過程等。試驗(yàn)結(jié)果表明,在大氣環(huán)境下,使用Al及Al-12Si(wt.%)釬料在超聲輔助的作用下能實(shí)現(xiàn)藍(lán)寶石之間的快速、可靠連接。在一定范圍內(nèi),接頭的剪切強(qiáng)度隨著超聲作用時(shí)間和超聲功率的增加而增強(qiáng),這是因?yàn)閮烧叩奶岣吣苡行Ц纳柒F料在陶瓷表面的潤濕,減少接頭中氣孔等缺陷的產(chǎn)生,增強(qiáng)了界面化學(xué)反應(yīng)。但當(dāng)超聲作用時(shí)間過長(≥60 s)及超聲功率過大(≥300 W)時(shí),接頭強(qiáng)度反而有所減小。研究發(fā)現(xiàn),該現(xiàn)象是由于在溫度較高的條件下,長時(shí)間高功率的超聲作用會(huì)對藍(lán)寶石基體產(chǎn)生損傷,并誘發(fā)微裂紋。Al作為釬料,超聲時(shí)間為5 s-60 s時(shí),接頭最大剪切強(qiáng)度為60.14 MPa。Al-12Si合金作為釬料時(shí),超聲時(shí)間為25 s時(shí)接頭剪切強(qiáng)度達(dá)最大值,為102.22 MPa。藍(lán)寶石在大氣環(huán)境下能夠?qū)崿F(xiàn)可靠連接的關(guān)鍵在于功率超聲的空化效應(yīng)與聲流作用。借助超聲空化,釬料表面的氧化膜被打碎并隨聲流移除,從而在藍(lán)寶石表面實(shí)現(xiàn)良好的鋪展和潤濕,同時(shí)超聲促進(jìn)藍(lán)寶石表面氧化鋁外延生長,促進(jìn)反應(yīng)潤濕的發(fā)生。超聲促進(jìn)熔融釬料對基體材料產(chǎn)生侵蝕作用,大量的基體氧化鋁顆粒擴(kuò)散進(jìn)入焊縫,在界面處形成榫形結(jié)構(gòu)。此外,Al-12Si作為釬料時(shí),超聲誘導(dǎo)焊縫內(nèi)元素再分布,在界面處形成Al-Si-O三元相,在接頭三維空間中形成自支撐結(jié)構(gòu)。超聲促使剝落的母材氧化鋁顆粒及誘發(fā)的藍(lán)寶石表面外延生長形成的納米陶瓷新相的共同生長形成最終的接頭。
[Abstract]:Sapphire single crystals with high strength, high hardness, wear resistance, corrosion resistance, high temperature resistance, good thermal conductivity and high light transmittance, so in the microelectronics, optoelectronic industry, semiconductor, Aerospace and other industries are often used as substrate materials or window materials. However, due to the difficulty of forming large sapphire at one time, the plasticity of sapphire itself is poor. Therefore, the application of sapphire in the field of large size components and complicated shape requirements is limited. One of the methods to solve this problem is to connect small size sapphire by welding and joining. Different shapes of sapphire connectors are made according to the requirements. Based on this, a supersonic assisted brazing method for rapid prototyping in atmospheric environment is proposed, in which sapphire single crystal is taken as the research object. The feasibility of ultrasonic assisted brazing of sapphire is systematically studied through a simple ultrasonic connection platform. The influence of different ultrasonic parameters on the joint performance is studied. The mechanism of ultrasonic action on weld microstructure and the evolution process of joint microstructure. The experimental results show that, in atmospheric environment, using Al and Al-12SiWt.) brazing filler metal can realize the speed between sapphire and sapphire. Reliable connection. In a certain range, the shear strength of the joint increases with the increase of ultrasonic time and ultrasonic power, because the increase of both can effectively improve the wetting of solder on the ceramic surface, The formation of porosity and other defects in the joint is reduced, and the interfacial chemical reaction is enhanced. However, when the ultrasonic action time is too long (鈮，

本文編號(hào)：1489719