本文關(guān)鍵詞： 超聲波焊接 光纖光柵傳感器 封裝 金屬化 傳感特性　出處：《南昌大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：光纖布拉格光柵(Fiber Bragg Grating,FBG)傳感器是光纖傳感器的典型代表,具有重量輕,體積小,抗電磁干擾等優(yōu)點,是智能結(jié)構(gòu)中傳感器最受歡迎的選擇之一。超聲波焊接具有固態(tài)成形、低溫、低壓、低能耗等優(yōu)點,能夠?qū)⒅T如FBG之類易碎的傳感器嵌入金屬基體,獲得可以感知自身溫度和應(yīng)變的智能結(jié)構(gòu)或傳感器件。本文對金屬化FBG傳感器超聲波焊接嵌入鋁合金進行了研究,具體包括:(1)宿主金屬超聲波焊接工藝優(yōu)化。通過鍍錫鋁合金與鎂合金的超聲波焊接工藝優(yōu)化和接頭界面組織分析,對焊接接頭形成機理進行研究,結(jié)果表明鍍錫層的加入有效地阻止了鎂鋁的相互擴散,抑制了硬脆的Mg-Al系金屬間化合物的生成,提高了鎂鋁超聲波焊接接頭強度,認(rèn)為焊接界面塑性變形引起的機械嵌合和高空位濃度加速了接頭界面的物理冶金過程是超聲波焊接接頭形成的主要原因;(2)FBG的金屬化保護。采用化學(xué)鍍鎳和電鍍鎳對FBG進行金屬化保護,化學(xué)鍍鎳層與光纖緊密結(jié)合,電鍍鎳層與化學(xué)鍍鎳層結(jié)合緊密,且成分相近,并對FBG金屬化后的傳感特性進行研究,研究結(jié)果表明,金屬化后FBG的溫度靈敏度為20.14 pm/℃,約為裸光柵的2倍,彎曲應(yīng)變靈敏度為2.341 pm/μ?;(3)FBG傳感器的超聲波點動焊接封裝工藝優(yōu)化。超聲波焊接時間45 ms,焊接壓力5.4 MPa,金屬鍍層厚度為45μm,成功將金屬化FBG嵌入厚度為0.3 mm的6061鋁合金,纖嵌入強度為1.89N,并對嵌入過程進行了討論;(4)超聲波焊接封裝的FBG傳感器熱壓傳感特性研究。FBG經(jīng)超聲波嵌入鋁合金后仍然保持良好的波形,由于焊接封裝時鋁合金發(fā)生塑性變形,FBG封裝時受機械壓縮而中心波長發(fā)生藍(lán)移;超聲波焊接封裝后FBG保持良好溫度、應(yīng)變傳感特性,平均溫度靈敏度為29.07 pm/℃,約為裸光柵的2.8倍,彎曲應(yīng)變靈敏度為0.0973 pm/μ?。
[Abstract]:Fiber Bragg grating (FBG) sensor is a typical optical fiber sensor, which has the advantages of light weight, small volume, anti-electromagnetic interference and so on. Ultrasonic welding has the advantages of solid state forming, low temperature, low pressure and low energy consumption. It can embed fragile sensors such as FBG into metal matrix. An intelligent structure or sensing device which can sense temperature and strain is obtained. In this paper, ultrasonic welding embedded aluminum alloy with metallized FBG sensor is studied. The ultrasonic welding process of host metal is optimized. The forming mechanism of welded joint is studied by optimizing the ultrasonic welding process of tin plated aluminum alloy and magnesium alloy and analyzing the interface structure of the joint. The results show that the addition of tin coating can effectively prevent the diffusion of magnesium and aluminum, inhibit the formation of hard and brittle intermetallic compound of Mg-Al system, and improve the strength of ultrasonic welding joint of magnesium and aluminum. It is considered that the mechanical chimney caused by plastic deformation of the welding interface and the high altitude concentration accelerate the physical metallurgical process of the joint interface, which is the main reason for the formation of the ultrasonic welding joint. Electroless nickel plating and electroplating nickel are used to metallize FBG. The electroless nickel plating layer is closely combined with optical fiber and electroplated nickel layer is close to electroless nickel plating layer and the composition is similar. The results show that the temperature sensitivity of the metallized FBG is 20.14 pm / 鈩，

本文編號：1482260