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超声波检测固体火箭发动机绝热层界面粘接 总被引:1,自引:1,他引:0
介绍了超声波检测固体火箭发动机壳体-绝热层界面粘接质量情况,并对其属特种复合材料粘接探伤进行了探讨,还提出了超声波检测由大面积的界面脱粘伤定量能力逐步肯定到小面积脱粘的确定。 相似文献
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《组合机床与自动化加工技术》2017,(10)
粘接层脱粘问题直接影响材料或结构的整体性能,需要采用合适的方法尽早检测。针对此问题,提出利用非线性超声无损检测方法对其进行检测,建立了粘结层失效的非线性超声测试系统,对脱粘不同程度的镁合金粘结层试件进行了试验研究,有效测量了表征粘接层失效程度的超声非线性系数β,结果表明超声非线性系数对镁合金粘结层失效非常敏感,且随脱粘程度呈二次函数关系增加;同时,建立了有限元仿真模型,对脱粘不同程度的镁合金粘结层试件进行了有限元数值仿真,仿真结果和实验结果在变化趋势上近似一致,进一步证明非线性超声检测技术可以用于粘接层界面失效的无损评价。 相似文献
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根据圆板强迫振动理论阐明了声阻探伤法何以能无损检测胶接结构的粘接质量,金属蜂窝结构面板上小凹坑处为何会产生“异常”指示,改变激励频率又何以能区分小凹坑处是否真的脱粘以及能达到此目的的充分条件. 相似文献
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有机粘结MoS2固体润滑膜耐腐蚀性能的研究 总被引:4,自引:0,他引:4
通过盐雾试验考察了底材表面磷化处理以及固体润滑膜的粘比和厚度对其腐蚀性的影响;同时对几种抗腐蚀添加剂和复合膜技术对固体润滑膜耐腐蚀性的改进进行了研究。结果表明:磷化处理可明显提高粘结固体泣滑膜的耐腐蚀性能,粘固比对润滑膜的耐腐蚀性有很大的影响,抗腐蚀添加剂和复合膜技术可显著固体润滑膜的耐腐蚀性能。 相似文献
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Hai-tao HU Yu-long LI Tao SUO Feng ZHAO Ying-gang MIAO Pu XUE Qiong DENG 《中国有色金属学会会刊》2014,24(5):1331-1336
Vibration tests were carried out on three types of stiffened aluminum plates with fully clamped boundaries under random base excitation. During the test, the response of the specimens was monitored using strain gauges. Based on the strain history, the accumulation of fatigue damage of the stiffened plates was estimated by means of the rainflow cycle counting technique and the Miner linear damage accumulation model in the time domain. Utilizing the change of natural frequencies, a nonlinear model was fitted for predicting the fatigue damage of plate and then the foregone failure criterion of 5% reduction in natural frequency is improved. The influence of section and spacing of the stiffeners on the vibration fatigue behavior of the aluminum plate was investigated. The results show that the fatigue life of aluminum plate increases with adding either T or L section riveted stiffeners. With the same cross-sectional area of stiffener, the T section stiffened plate shows longer fatigue life than L section stiffened plate. Meanwhile, the vibration fatigue life also shows great sensitivity to the spacing between the stiffeners. 相似文献
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采用直接水冷半连续铸造法制备 4045/3004/4045 铝合金三层复合锭坯。考察复合界面附近的温度场分布,并研究复合界面的宏观形貌、微观组织及界面两侧的成分分布。结果表明,在冷却板的作用下,界面附近形成一层具有一定厚度的半固态层,从而保证半连续铸造过程制备复合锭坯的顺利实现。两种合金在界面处较好地冶金结合在一起。界面力学性能测试结果表明,复合界面的抗拉强度和剪切强度分别为 105 和 88 MPa,这进一步证明了复合界面的结合是一种冶金结合。 相似文献
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《Acta Materialia》2003,51(12):3375-3384
In this paper, the constitutive relation of particulate-reinforced viscoelastic composite materials is studied by considering the evolution of microvoids. Owing to the difference in mechanical properties between matrix and second phase particles, debonding of particle-matrix interface may occur under the condition of high stress triaxiality. This kind of damage will lead to the nucleation and growth of microvoids. The reinforcing effect due to rigid particles and the weakening effect due to microvoids caused by debonding on the overall mechanical properties of particulate-reinforced composites are investigated. Using the energy criterion of interfacial debonding, an expression for the nucleation rate of microvoids is suggested. Then, the growth of these voids is studied by means of Eshelby’s equivalent inclusion method. It is shown that the strain of the microvoids depends not only on the remote strain history but also on their nucleation time. By considering the effect of nucleation time, a new definition of an average strain of microvoids is given. According to the Mori–Tanaka scheme, a macroscopic constitutive relation of the composite material is finally derived. The results show that macroscopic strain rate, particle-size dispersity, relaxation time of matrix, and interface adhesive strength all play key roles in the overall mechanical properties of particulate-reinforced composites. 相似文献
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本文利用电镀工艺制备了表面镀镍碳纤维,通过双辊铸轧短流程成型工艺成功制备了连续碳纤维增强铝基(Cf/Al)复合材料板,研究了浇注温度对铸轧复合材料板的微观组织、界面特征、断口形貌和力学性能的影响。结果表明,浇注温度为963~983K,轧制速度为2.7m/min,辊缝为2.0mm的条件下可制备出表面平整、无明显表面缺陷的Cf/Al铸轧复合材料板;其中,浇注温度为973K时,碳纤维与铝基体之间界面结合良好;纤维表面金属镍层明显改善了碳纤维与铝基体之间的浸润性,镍镀层还有效抑制了Al4C3脆性相的产生,使Cf/Al复合材料板力学性能大幅提升,其中浇注温度973K铸轧的Cf/Al复合材料板抗拉强度比初始的38.2MPa提高了87.4%。 相似文献
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研究了铜铝复合材料在质量分数为5%的NaCl中性盐雾中进行间歇性通电时的加速腐蚀过程,通过失重分析法、SEM、EDS、XRD以及电化学检测法分析了铜铝复合板的腐蚀机制与电流影响机制。结果表明,铜铝复合板界面处发生电偶腐蚀倾向比远离界面处铝基体更严重,在0~50A范围内,电流对复合板起到加速腐蚀作用,电流越大,加速作用越明显。相比于全程通电的试样,在25A电流下作用48h内,间歇性通电的试样腐蚀更严重。 相似文献
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钛合金表面激光熔化沉积钛基复合材料涂层的组织及性能 总被引:3,自引:0,他引:3
通过激光熔化沉积TA15+30%TiC(体积分数)混合粉末,在TA15钛合金表面制备出钛基复合材料涂层,分析了涂层的组织、硬度及界面结合强度。结果表明,激光熔化沉积过程中原始TiC颗粒发生溶解,并在凝固过程中重新析出细小的TiC,TiC有等轴状及枝晶两种形态,涂层中存在部分未熔的TiC颗粒;涂层硬度达HRC 60;涂层与基体界面为完全冶金结合,涂层的界面结合强度大于310 MPa,抗剪切强度为330 MPa;经弯曲及热震试验后,涂层未出现剥落现象,表明涂层与基体具有很好的相容性 相似文献