【作者】 陈敏；

【导师】 王美荣；

【作者基本信息】 哈尔滨工业大学 ， 材料与化工（专业学位）， 2022， 硕士

【摘要】 K9玻璃作为工业光学玻璃的一种,可广泛应用于光学镀膜、各种高质量光学窗口及元器件。由于玻璃本身具有脆性,可与其他材料形成复合构件来提高自身使用性能。金属-玻璃复合构件如今已广泛应用于航空航天、生物医疗、军事等领域。Ti Al合金因其密度低、强度高等优点,是航空航常用的材料之一。基于K9玻璃的光学特性,本文提出一种Ti Al合金与K9玻璃的间接钎焊方法,对空间相机主镜反射镜结构进行轻量化设计。先对K9玻璃进行钎焊连接,分析其界面组织和力学性能;然后在Ti Al合金表面进行涂层制备,选出最佳涂层工艺;最后进行Ti Al合金与K9玻璃的间接钎焊,并结合界面组织变化规律,阐述Ti Al/K9体系的连接机理。利用机械球磨法制得的Sn0.3Ag0.7Cu-x%Ti(x=1,2,3,4,6,8,wt.%)粉末,在不同温度和时间参数下钎焊K9玻璃。钎焊接头典型界面结构为:K9/Ti O2+Ti Si/β-Sn+Cu6Sn5+Ti2Sn3/Ti O2+Ti Si/K9。Ti通过与K9玻璃中的Si O2反应生成Ti O2及Ti Si化合物,提高了钎料在K9玻璃表面的铺展能力。界面中Ti2Sn3化合物与反应层的变化规律与液相钎料中溶解的Ti含量有关,液相钎料中溶解的Ti含量越多,扩散至K9玻璃界面参与反应的Ti越多,形成的Ti O2+Ti Si反应层越厚,界面析出的Ti2Sn3化合物越少。随着温度的升高或保温时间延长,因钎料的流动性变强,钎缝宽度逐渐减小,钎料中溶解的Ti增多,使钎料/K9界面反应层不断增厚。在3%Ti-650℃-10 min条件下,接头剪切强度最高,约为19.3 MPa,断裂在玻璃一侧。在900~980℃的温度范围内,利用Sn0.3Ag0.7Cu粉末对Ti Al表面进行了涂层制备。Ti Al溶解后与液相Sn0.3Ag0.7Cu钎料作用,在冷却过程析出Ti6Sn5,Ti2Sn3,Al3Ti,Al5Cu Ti2,Al4Cu9等化合物。随着温度的升高或保温时间延长,Sn0.3Ag0.7Cu钎料在Ti Al表面的润湿角逐渐减小,Ti Al一侧溶解层逐渐增厚,当参数超过最佳工艺(920℃-20 min)时,溶解层会因热应力出现开裂现象。利用Sn0.3Ag0.7Cu-3%Ti钎料在不同温度和保温时间的条件下对涂层处理后的Ti Al合金与K9玻璃进行了连接,所得钎焊接头的典型界面组织为:Ti Al/Ti6Sn5+Ti2Sn3+Al3Ti/Al5Cu Ti2+Al4Cu9+Ti6Sn5+Ti2Sn3+β-Sn/Ti2Sn3+β-Sn/K9。钎料熔化后一方面与K9玻璃一侧反应生成Ti O2及Ti Si化合物形成冶金结合,另一方面钎料经铺展后与涂层中的β-Sn互相融合得以与Ti Al一侧连接。随着温度升高或保温时间延长,接头强度先升高后降低,在670℃保温20 min时所得接头的平均剪切强度最高,约为9.6 MPa。此时钎料与母材反应充分,结合良好,断裂发生于Ti Al溶解层界面的化合物区域,呈脆性断裂。更多还原

【Abstract】 As a kind of industrial optical glass,K9 glass can be widely used in optical coating,various high-quality optical windows,and components.Due to the brittle nature of glass,it can form composite components with other materials to improve its performance.Ti Al alloy is one of the common materials used in aerospace because of its low density and high strength.This paper proposed an indirect brazing method between Ti Al alloy and K9 glass for the lightweight design of the space camera main mirror reflector structure based on the optical properties of K9 glass.Firstly,The brazing of K9 glass was carried out to analyze its interfacial organization and mechanical properties.Secondly,a coating was processed to the surface of the Ti Al alloy,and the best coating process was chosen.Finally,the indirect brazing of Ti Al alloy and K9 glass was performed,and the Ti Al/K9 system joinning mechanism was elaborated by combining the change law of interfacial organization.Sn0.3Ag0.7Cu-x%Ti(x=1,2,3,4,6,8,wt.%)powder produced by the mechanical ball milling method was used to braze K9 glass under different temperature and time parameters.The typical interfacial structure of the brazed joints was K9/Ti O2+Ti Si/β-Sn+Cu6Sn5+Ti2Sn3/Ti O2+Ti Si/K9.Ti improved the spreading ability of the brazing material on the surface of K9 glass by reacting with Si O2 in K9 glass to form Ti O2 and Ti Si chemistry.The dissolved Ti content in the liquid phase brazing material would affect the variation law of Ti2Sn3 compound and reaction layer at the interface.The more Ti dissolved in the liquid phase brazing material,the more Ti diffused to the K9 glass interface to participate in the reaction,the thicker Ti O2+Ti Si reaction layer formed,and the less Ti2Sn3 compound precipitated from the interface.The width of the brazing seam gradually decreased as the temperature rised or the holding time was prolonged because the fluidity of the brazing material increases and the dissolved Ti in the brazing material increased,causing the reaction layer at the brazing material/K9 interface to thicken.Under the 3%Ti-650 ℃-10 min condition,the joint shear strength was the highest of 19.3MPa compared to the other parameters with the fracture appeared on the glass side.The Ti Al surface was prepared by coating with Sn0.3Ag0.7Cu powder in the temperature range of 900~980 ℃.Ti Al dissolved and interacted with the liquid phase Sn0.3Ag0.7Cu brazing material,and compounds such as Ti6Sn5,Ti2Sn3,Al3 Ti,Al5Cu Ti2,and Al4Cu9 were precipitated during cooling.As the temperature increases or the holding time is extended,the wetting angle of Sn0.3Ag0.7Cu brazing material on the Ti Al surface gradually decreases and the dissolution layer on the Ti Al side gradually thickens,and when the parameters exceed the optimal process(920 ℃-20 min),the dissolution layer will crack due to thermal stress.The pre-coated Ti Al was joined with K9 glass using Sn0.3Ag0.7Cu-3% Ti filler at different temperatures and holding times.The typical interfacial organization of the brazed joints was: Ti Al/Ti6Sn5+Ti2Sn3+Al3Ti/Al5 Cu Ti2+Al4Cu9+Ti6Sn5+Ti2Sn3+β-Sn/Ti2Sn3+β-Sn/K9.On the one hand,after melting,the brazing filler reacted with the Si O2 in the K9 glass to produce Ti O2 and Ti Si forming a metallurgical bond.On the other hand,the brazing filler fused with the β-Sn in the coating after spreading to joinning with the Ti Al side.At the condition of 670 ℃/20 min,the average shear strength of Ti Al/K9 joints was the highest,about 9.6 MPa.At this time,the brazing filler reacted sufficiently with the base metal to form a satisfactory joint.The fracture occurred in the compounds region at the interface of the Ti Al dissolution layer,which presented brittle characteristic.更多还原