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Research on the creep damage and interfacial failure of dissimilar metal welded joint between 10Cr9Mo1VNbN and 12Cr1MoV steel 被引量:4
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作者 张建强 赵海燕 +3 位作者 吴甦 鹿安理 王煜 章应霖 《China Welding》 EI CAS 2004年第1期65-70,共6页
The mechanical properties, creep damage, creep rupture strength and features of interfacial failures of welded joints between martensite (SA213T91) and pearlite steel (12Cr1MoV) have been investigated by means of argo... The mechanical properties, creep damage, creep rupture strength and features of interfacial failures of welded joints between martensite (SA213T91) and pearlite steel (12Cr1MoV) have been investigated by means of argon tungsten pulsed arc welding, high temperature accelerated simulation, creep rupture, mechanical property tests and scanning electronic microscope (SEM). The research results indicate that the mechanical properties of overmatched and medium matched joint deteriorate obviously, and they are susceptible to creep damage and failure after accelerated simulation operation 500 h, in the condition of preheat 250℃, and post welding heat treatment 750℃×1 h. However, the mechanical properties of undermatched joint are the best, the interfacial failure tendency of undermatched welded joint is less than those of medium and overmatched welded joint. Therefore, it is reasonable that low alloy material TR31 is used as the filler metal of weld between SA213T91and 12Cr1MoV steel. 展开更多
关键词 dissimilar metal welded joint creep damage interfacial failure creep rupture strength
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Quantitative Metal Magnetic Memory Reliability Modeling for Welded Joints 被引量:6
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作者 XING Haiyan DANG Yongbin +1 位作者 WANG Ben LENG Jiancheng 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2016年第2期372-377,共6页
Metal magnetic memory(MMM) testing has been widely used to detect welded joints. However, load levels, environmental magnetic field, and measurement noises make the MMM data dispersive and bring difficulty to quanti... Metal magnetic memory(MMM) testing has been widely used to detect welded joints. However, load levels, environmental magnetic field, and measurement noises make the MMM data dispersive and bring difficulty to quantitative evaluation. In order to promote the development of quantitative MMM reliability assessment, a new MMM model is presented for welded joints. Steel Q235 welded specimens are tested along the longitudinal and horizontal lines by TSC-2M-8 instrument in the tensile fatigue experiments. The X-ray testing is carried out synchronously to verify the MMM results. It is found that MMM testing can detect the hidden crack earlier than X-ray testing. Moreover, the MMM gradient vector sum K_(vs) is sensitive to the damage degree, especially at early and hidden damage stages. Considering the dispersion of MMM data, the K_(vs) statistical law is investigated, which shows that K_(vs) obeys Gaussian distribution. So K_(vs) is the suitable MMM parameter to establish reliability model of welded joints. At last, the original quantitative MMM reliability model is first presented based on the improved stress strength interference theory. It is shown that the reliability degree R gradually decreases with the decreasing of the residual life ratio T, and the maximal error between prediction reliability degree R_1 and verification reliability degree R_2 is 9.15%. This presented method provides a novel tool of reliability testing and evaluating in practical engineering for welded joints. 展开更多
关键词 metal magnetic memory quantitative reliability modeling welded joints
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Numerical Simulation on Interfacial Creep Failure of Dissimilar Metal Welded Joint between HR3C and T91 Heat-Resistant Steel 被引量:1
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作者 张建强 TANG Yi +3 位作者 ZHANG Guodong ZHAO Xuan GUO Jialin LUO Chuanhong 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2016年第5期1068-1074,共7页
The maximum principal stress, von Mises equivalent stress, equivalent creep strain, stress triaxiality in dissimilar metal welded joints between austenitic(HR3C) and martensitic heat-resistant steel(T91) are simul... The maximum principal stress, von Mises equivalent stress, equivalent creep strain, stress triaxiality in dissimilar metal welded joints between austenitic(HR3C) and martensitic heat-resistant steel(T91) are simulated by FEM at 873 K and under inner pressure of 42.26 MPa. The results show that the maximum principal stress and von Mises equivalent stress are quite high in the vicinity of weld/T91 interface, creep cavities are easy to form and expand in the weld/T91 interface. There are two peaks of equivalent creep strains in welded joint, and the maximum equivalent creep strain is in the place 27-32 mm away from the weld/T91 interface, and there exists creep constrain region in the vicinity of weld/T91 interface. The high stress triaxiality peak is located exactly at the weld/T91 interface. Accordingly, the weld/T91 interface is the weakest site of welded joint. Therefore, using stress triaxiality to describe creep cavity nucleation and expansion and crack development is reasonable for the dissimilar metal welded joint between austenitic and martensitic steel. 展开更多
关键词 dissimilar metal welded joint maximum principal stress equivalent stress creep strain stress triaxiality
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Microstructural Evolution on the T91 Dissimilar Metal Joints during Creep Rupture Tests
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作者 GuangminLUO JianshengWU QingsenMENG 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2004年第4期383-386,共4页
T91 steel is one of the new materials presently employed in power plant pipe components. The creep rupture strength and microstructure of the T91+10CrMo910 and T91+13CrMo44 welded joints were analyzed during creep rup... T91 steel is one of the new materials presently employed in power plant pipe components. The creep rupture strength and microstructure of the T91+10CrMo910 and T91+13CrMo44 welded joints were analyzed during creep rupture tests. Creep transgranular ductile rupture occurred at the 10CrMo910 matrix in the T91+10CrMo910 welded joints and creep intergranular brittle rupture occurred at the 13CrMo44 HAZ in the T91+13CrMo44 joints. Microhardness measurements showed high hardness at the heat affected zone (HAZ) of T91 and a sharply drop at the 13CrMo44 HAZ during creep rupture. The metallographic tests showed that no obvious microstructure degradation was observed in the 10CrMo910 HAZ and matrix, while creep cracks appeared at the 13CrMo44 HAZ. T91 steel had relatively high creep resistant strength in the welded joints tested. Recovery occurred in the T91 HAZ with the growth of subgrain size and the decrease of dislocation density during creep. It was concluded that the dissimilar joints of T91 and low alloy heat-resistant steel should have close creep strength matching to increase the service life of the overall joints at elevated temperature. 展开更多
关键词 T91 steel Dissimilar metal joint Creep rupture test
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Direct Comparison between Tensile Strength and Flexural Strength of Ceramic/Metal Brazing Joint
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作者 冼爱平 斯重遥 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 1992年第1期30-34,共5页
A design of the sandwich joint,steel/ ceramic/steel,was made for direct comparison be- tween tensile and flexural strength of ceramic/metal joint.The flexural strength is about twice as high as the tensile strength fo... A design of the sandwich joint,steel/ ceramic/steel,was made for direct comparison be- tween tensile and flexural strength of ceramic/metal joint.The flexural strength is about twice as high as the tensile strength for the same joint.The results also showed that the flexural test is more excellent than tensile test for joint with a high interracial bond strength. 展开更多
关键词 ceramic/metal brazing joint BONDING STRENGTH
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Progressive Failure Analysis of Composite/Aluminum Riveted Joints Subjected to Pull-Through Loading
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作者 Yuxing Yang Yongjie Bao +2 位作者 Xueshu Liu Jinlong Wang Fengming Du 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2023年第1期129-138,共10页
Out-of-plane mechanical properties of the riveted joints restrict the performance of the wing box assembly of airplane.It is necessary to investigate the pull-through performance of the composite/metal riveted joints ... Out-of-plane mechanical properties of the riveted joints restrict the performance of the wing box assembly of airplane.It is necessary to investigate the pull-through performance of the composite/metal riveted joints in order to guide the riveting design and ensure the safety of the wing box assembly.The progressive failure mechanism of composite/aluminum riveted joint subjected to pull-through loading was investigated by experiments and finite element method.A progressive damage model based on the Hashin-type criteria and zero-thickness cohesive zone method was developed by VUMAT subroutine,which was validated by both open-hole tensile test and three-point bending test.Predicted load-displacement response,failure modes and damage propagation were analysed and compared with the results of the pull-through tests.There are 4 obvious characteristic stages on the load-displacement curve of the pull-through test and that of the finite element model:first load take-up stage,damage stage,second load take-up stage and failure stage.Relative error of stiffness,first load peak and second load peak between finite element method and experiments were 8.1%,-3.3%and 10.6%,respectively.It was found that the specimen was mainly broken by rivet-penetration fracture and delamination of plies of the composite laminate.And the material within the scope of the rivet head is more dangerous with more serious tensile damages than other regions,especially for 90°plies.This study proposes a numerical method for damage prediction and reveals the progressive failure mechanism of the hybrid material riveted joints subjected to the pull-through loading. 展开更多
关键词 Composite/metal joints Riveted joints Pull-through test Progressive damage model
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Strength and interfacial microstructure of Si3N4 joint brazed with amorphous Ti-Zr-Ni-Cu filler metal
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作者 邹家生 周权 吕思聪 《China Welding》 EI CAS 2009年第1期57-61,共5页
In this paper, the vacuum brazing of Si3N4 ceramic was carried out with Ti40Zr25Ni15Cu20 amorphous filler metal. The interfacial microstructure was investigated by scanning electron microscopy ( SEM ), energy disper... In this paper, the vacuum brazing of Si3N4 ceramic was carried out with Ti40Zr25Ni15Cu20 amorphous filler metal. The interfacial microstructure was investigated by scanning electron microscopy ( SEM ), energy dispersive spectroscopy (EDS) etc. According to the analysis, the interface reaction layer was mode up of TiN abut on the ceramic and the Ti-Si, Zr-Si compounds. The influence of brazing temperature and holding time on the joint strength was also studied. The results shows that the joint strength first increased and then decreased with the increasing of holding time and brazing temperature. The joint strength was significantly affected by the thickness of the reaction layer. Under the same experimental conditions, the joint brazed with amorphous filler metal exhibits much higher strength compared with the one brazed with crystalline filler metal with the same composition. To achieve higher joint strength at relatively low temperature, it is favorable to use the amorphous filler metal than the crystalline filler metal. 展开更多
关键词 Ti-Zr-Ni-Cu amorphous filler metal Si3 N4 ceramics joint strength interfacial structure
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Effect of joining temperature on microstructure and properties of diffusion bonded Mg/Al joints 被引量:5
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作者 尚晶 王克鸿 +3 位作者 周琦 张德库 黄俊 葛佳棋 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第8期1961-1966,共6页
The joining of AZ31B Mg alloy to 6061 Al alloy was investigated at different joining temperatures by vacuum diffusion bonding method. The microstructures of Mg/Al dissimilar joints were studied by means of optical mic... The joining of AZ31B Mg alloy to 6061 Al alloy was investigated at different joining temperatures by vacuum diffusion bonding method. The microstructures of Mg/Al dissimilar joints were studied by means of optical microscopy (OM), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX). The results show that the thickness of each layer in the diffusion zone increases with the increase of joining temperature, and the microstructure changes obviously. At joining temperature of 440 °C, the diffusion zone is composed of Mg2Al3 layer and Mg17Al12 layer. At joining temperatures of 460 and 480 °C, the diffusion zone is composed of Mg2Al3 layer, Mg17Al12 layer, eutectic layer of Mg17Al12 and Mg-based solid solution. The width of high-hardness zone in the joint increases with increasing joining temperature, and the micro-hardnesses at different locations in the diffusion zone are significantly different. The joining temperature of 440 °C offers the highest tensile strength of 37 MPa, and the corresponding joint exhibits brittle fracture at the intermetallic compound layer of Mg17Al12. 展开更多
关键词 vacuum diffusion bonding 6061 aluminum alloy AZ31 magnesium alloy dissimilar metal joint MICROSTRUCTURE mechanical property
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纤维增强复合材料-金属混合连接接头疲劳性能研究进展 被引量:1
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作者 宋建辉 虞筱琛 +3 位作者 祝颖丹 吴化平 张雄军 陈刚 《复合材料科学与工程》 CAS 北大核心 2024年第9期105-112,共8页
纤维增强复合材料由于其优异的力学性能已被广泛应用于各种轻量化场合。通常情况下,复合材料在实际应用中需要和金属等异质材料进行连接,其中混合连接接头相比胶接、传统机械连接具有更优异的力学性能。疲劳寿命是影响纤维增强复合材料... 纤维增强复合材料由于其优异的力学性能已被广泛应用于各种轻量化场合。通常情况下,复合材料在实际应用中需要和金属等异质材料进行连接,其中混合连接接头相比胶接、传统机械连接具有更优异的力学性能。疲劳寿命是影响纤维增强复合材料-金属混合连接接头服役性能的关键,本文对混合连接接头各部分材料的疲劳性能进行了分析,探讨了混合连接接头疲劳寿命预测方法,分析了影响混合连接接头疲劳性能的重要因素,并对其发展趋势进行了总结和展望。 展开更多
关键词 纤维增强复合材料 金属 混合连接 疲劳性能 寿命预测
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丙烯酸-壳聚糖凝胶负载废酵母处理重金属离子
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作者 王霏 李升军 +4 位作者 崔荣煜 吴金秋 楚飞虎 曹丰 冯芳 《环境科学与技术》 CAS CSCD 北大核心 2024年第4期62-70,共9页
目前,重金属废水处理技术研究中采用的生物吸附剂大多呈粉体状,会因活性结构特性不易保持,并且固液分离损失大、能耗高,导致其在重金属废水处理工程化应用受到制约。文章以丙烯酸和壳聚糖为原料,通过紫外交联法制备块体凝胶并负载废酵... 目前,重金属废水处理技术研究中采用的生物吸附剂大多呈粉体状,会因活性结构特性不易保持,并且固液分离损失大、能耗高,导致其在重金属废水处理工程化应用受到制约。文章以丙烯酸和壳聚糖为原料,通过紫外交联法制备块体凝胶并负载废酵母作为生物吸附剂。研究紫外交联丙烯酸复合壳聚糖制成凝胶的优化条件,当丙烯酸与壳聚糖的比值为30∶1,加入15%质量百分比的N-N亚甲基双丙烯酰胺作为交联剂,再加入2%质量百分比的1173D作为光引发剂,此时制备出的含废酵母丙烯酸复合壳聚糖基水凝胶具有较好的溶胀性能和孔洞结构,对于Zn、Cd或Pb离子吸附去除率分别为27.8%、30.8%和38.8%。凝胶包埋废酵母后,去除水中低浓度的重金属Zn、Cd和Pb离子均有提升,对Pb^(2+)溶液的综合吸附去除率达到74.8%。丙烯酸-壳聚糖凝胶作为生物吸附剂载体实现简易快速包埋成型,块体形状有利于后续载体回收。 展开更多
关键词 生物吸附 废酵母 丙烯酸 壳聚糖 紫外交联 凝胶 重金属废水
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激光功率对铝/铜激光熔钎焊接头组织及性能的影响
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作者 杜道忠 张超 周宇浩 《机械工程材料》 CAS CSCD 北大核心 2024年第5期26-32,共7页
采用激光熔钎焊方法对5052铝合金和T2紫铜进行对接试验,研究了激光功率(2000,2200,2400,2600,2800 W)对接头显微组织和力学性能的影响。结果表明:不同激光功率下接头铜侧钎焊区组织均以柱状晶为主,随着激光功率的增加,焊缝区树枝晶由细... 采用激光熔钎焊方法对5052铝合金和T2紫铜进行对接试验,研究了激光功率(2000,2200,2400,2600,2800 W)对接头显微组织和力学性能的影响。结果表明:不同激光功率下接头铜侧钎焊区组织均以柱状晶为主,随着激光功率的增加,焊缝区树枝晶由细针状转变为雪花状;铜侧钎焊区由界面层和金属间化合物层组成,2000,2600 W激光功率下的界面层主要为AlCu相,金属间化合物层主要为Al_(4)Cu_(9)相,2400 W激光功率下的界面层主要由AlCu相和CuZn相组成,金属间化合物层主要为CuZn_(5)相;焊缝区主要由Al_(4.2)Cu_(3.2) Zn_(0.7)和Al_(0.71)Zn_(0.29)相组成。随着激光功率的增加,金属间化合物层厚度增加。激光功率对铜侧钎焊区的显微硬度影响较大,各接头的最高显微硬度均出现在铜侧钎焊区。随着激光功率的增加,接头最高硬度增加,抗拉强度先增大后减小;当激光功率为2400 W时,接头的抗拉强度最大,达到铝合金母材的92%,此时接头在靠近铝合金母材处断裂,而其他激光功率下制备的接头均在铜侧钎焊区和焊缝区处断裂。 展开更多
关键词 铝/铜异种金属接头 激光熔钎焊 激光功率 显微组织 力学性能
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多金属暴露与骨关节疾病的关联研究 被引量:1
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作者 龚雅洁 陈子慧 +5 位作者 吴珊 纪桂圆 李律容 刘涛 马文军 陈青松 《环境卫生学杂志》 2024年第9期762-769,F0003,共9页
目的探讨广东省居民多金属暴露与骨关节疾病的相关性。方法采用以社区为基础的横断面研究方法,从广东省11个地区招募3063名成年人,并测量了13种金属的血液浓度,以评估内暴露水平。运用多变量Logistic回归分析血液金属水平与骨关节疾病... 目的探讨广东省居民多金属暴露与骨关节疾病的相关性。方法采用以社区为基础的横断面研究方法,从广东省11个地区招募3063名成年人,并测量了13种金属的血液浓度,以评估内暴露水平。运用多变量Logistic回归分析血液金属水平与骨关节疾病的关系。结果在单金属模型中,血铬、锌和铜浓度与骨关节疾病风险呈现显著剂量反应关系(All P_(-trend)≤0.05)。进一步通过多金属模型发现,与血铜和锌浓度处于低水平组(Q1)人群相比,最高水平组(Q4)血铜、锌浓度与骨关节疾病有关(OR=0.78,95%CI:0.53~0.93;OR=1.38,95%CI:1.07~1.34)。结论人群暴露环境铜和锌与骨关节疾病有关,研究结果需要在更大的人群研究中验证。 展开更多
关键词 多金属暴露 环境污染 骨关节疾病
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海洋平台支撑板异种金属焊接试验研究
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作者 徐和林 王江华 廖娟 《精密成形工程》 北大核心 2024年第9期201-208,共8页
目的结合Q245R/Q690D 2种材料的优势研究其焊接接头性能,获得最优的焊接和后热处理工艺参数。方法以某海洋平台建造为背景,选用E50-6焊丝、J形坡口设计对Q245R/Q690D中厚板多道次焊接进行试验研究。在8、12、16、20 kJ/cm热输入下,对接... 目的结合Q245R/Q690D 2种材料的优势研究其焊接接头性能,获得最优的焊接和后热处理工艺参数。方法以某海洋平台建造为背景,选用E50-6焊丝、J形坡口设计对Q245R/Q690D中厚板多道次焊接进行试验研究。在8、12、16、20 kJ/cm热输入下,对接头进行力学性能测试和微观组织观察;为细化接头组织、提高综合力学性能,对最佳热输入下的接头进行不同温度的后热处理,后热处理温度分别为250、350、580℃并保温2 h,进一步观察接头的性能和微观组织。结果焊态下拉伸断裂均发生在Q245R母材侧,在12 kJ/cm热输入下,焊缝表面硬度在338HV左右,焊缝冲击功为172 J;在20 kJ/cm热输入下,冲击功下降至82.7 J,组织粗大且呈板条状。在250、350℃回火能够降低表面硬度,同时焊缝冲击功较焊态的略有上升,最大增加了21 J;在580℃回火后,内部晶粒粗大,焊缝表面硬度增大,最大为448HV,较焊态的提高了32.5%,同时冲击功显著下降,下降至80 J,下降约53.5%。结论Q245R/Q690D中厚板多道次焊接热输入采用12 kJ/cm为宜,同时焊后对接头进行250~350℃回火并保温2 h为推荐后热处理方式。 展开更多
关键词 异种金属 焊接接头 多道次焊接 接头性能 Q245R/Q690D
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装配式钢结构连接节点的有限元传热计算分析研究
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作者 刘然 唐伟明 +2 位作者 徐骞 林朋朋 黄祁聪 《工程建设与设计》 2024年第7期39-43,共5页
在绿色低碳建设的发展理念下,装配式钢结构建筑技术大力发展。钢结构建筑连接节点构造复杂,金属连接件种类多,所形成的热损失量不易估算。论文基于有限元传热分析方法对钢结构预制混凝土墙板楼板连接节点进行了热工性能模拟计算,详细核... 在绿色低碳建设的发展理念下,装配式钢结构建筑技术大力发展。钢结构建筑连接节点构造复杂,金属连接件种类多,所形成的热损失量不易估算。论文基于有限元传热分析方法对钢结构预制混凝土墙板楼板连接节点进行了热工性能模拟计算,详细核算了由钢结构主体形成的结构性热桥以及由金属连接件形成的点热桥所造成的热损失。由于钢制连接件具有多维热传导属性,通过模拟计算结果可见,即使每个部件均采用了较好的断热桥措施,组装后形成的整体构造热损失仍是不可忽视。 展开更多
关键词 装配式钢结构建筑 复合保温外墙板 热桥节点 金属连接件 热工性能 有限元分析方法
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焊接速度对铝合金/铜激光熔钎焊接头组织及性能的影响
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作者 周海波 蒋翔 周宇浩 《机械工程材料》 CAS CSCD 北大核心 2024年第10期85-91,共7页
采用激光熔钎焊在不同焊接速度(4,5,6,7,8 mm·s^(-1))下对5052铝合金和T2铜进行对接焊,研究了焊接速度对接头宏观形貌、显微组织、显微硬度、抗拉强度及拉伸断裂机理的影响。结果表明:随着焊接速度增加,激光熔钎焊接头的焊缝成形... 采用激光熔钎焊在不同焊接速度(4,5,6,7,8 mm·s^(-1))下对5052铝合金和T2铜进行对接焊,研究了焊接速度对接头宏观形貌、显微组织、显微硬度、抗拉强度及拉伸断裂机理的影响。结果表明:随着焊接速度增加,激光熔钎焊接头的焊缝成形先变优后变差,当焊接速度为6 mm·s^(-1)时焊缝成形最佳;随着焊接速度增加,接头中树枝状Al-Cu共晶组织变少,Zn-Al共晶组织变多,当焊接速度为6 mm·s^(-1)时接头铜侧界面反应区出现Al_(4)Cu_(9)和Al_(2)Cu金属间化合物,熔焊区由α-Al固溶体、η-Zn固溶体、Al-Cu共晶组织和Zn-Al共晶组织组成;随着焊接速度增加,铝合金/铜激光熔钎焊接头熔焊区硬度变化不大,铜侧界面反应区硬度下降,接头抗拉强度先增大后减小,拉伸断裂模式按照解理断裂、准解理断裂、韧性断裂、准解理断裂顺序依次变化,当焊接速度为6 mm·s^(-1)时抗拉强度(212 MPa)最大,接头发生韧性断裂。 展开更多
关键词 铝/铜异种金属接头 激光熔钎焊 焊接速度 显微组织 力学性能
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Ni元素对Zn-22Al药芯钎料用于Cu/Al钎焊接头组织和力学性能的影响
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作者 王徐炳 黄魏青 +4 位作者 王思鸿 卜永周 查心婧 刘薇 沈杭燕 《中国计量大学学报》 2024年第3期487-495,共9页
目的:研究Ni元素对Zn-Al药芯焊丝熔化特性、铺展性能的影响。方法:在钎剂中添加一定比例的Ni粉,在钎焊过程中形成Cu/Al接头的Ni合金化,分析不同含量Ni元素添加对Zn-22Al钎料以及Cu/Al异种合金钎焊接头的性能及显微组织的影响。结果:Ni... 目的:研究Ni元素对Zn-Al药芯焊丝熔化特性、铺展性能的影响。方法:在钎剂中添加一定比例的Ni粉,在钎焊过程中形成Cu/Al接头的Ni合金化,分析不同含量Ni元素添加对Zn-22Al钎料以及Cu/Al异种合金钎焊接头的性能及显微组织的影响。结果:Ni粉添加可使Zn-22Al钎料在Al板上的铺展性能得到提升,当添加量质量分数为5%时钎料铺展性能提升26.75%;当添加量质量分数为7%时,用于Cu/Al钎焊的接头抗拉强度相较于未添加Ni粉焊接接头强度提升61.79%。结论:Ni粉添加可有效改善Zn-22Al焊缝的显微组织,体现为主晶相的细化,富Zn边界相的减少,促进主晶团之间形成层片状共析组织,以及减小了Cu侧生成的铜铝金属间化合物脆性相的厚度。 展开更多
关键词 ZN-AL钎料 Ni原位掺混 铜铝异种接头 力学性能 显微组织
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永久式金属挤压接头连接件密封性能的研究
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作者 张旭 田凤杰 +1 位作者 江晓宇 曾文军 《现代机械》 2024年第4期40-46,共7页
为了研究永久式金属挤压接头连接件挤压连接密封性能,分析了不同挤压量对航空管路连接密封性能的影响。建立6061接头体、7075挤压环、6061导管的连接模型,提出导管有效密封的判定条件。通过有限元仿真不同挤压量的挤压成型过程,分析得... 为了研究永久式金属挤压接头连接件挤压连接密封性能,分析了不同挤压量对航空管路连接密封性能的影响。建立6061接头体、7075挤压环、6061导管的连接模型,提出导管有效密封的判定条件。通过有限元仿真不同挤压量的挤压成型过程,分析得出在挤压过程中不同挤压量下接头体、挤压环、导管之间的最大和最小接触应力和塑性变形。同时进行了同一产品结构单边相对挤压量分别为0.8 mm、1 mm的密封性能对比试验验证。结果验证了模型建立和有限元仿真的准确性,单边挤压量的增加会使零件的密封性能增强;接头体主要发生塑性变形,导管和挤压环主要发生弹性变形,接头体内部密封齿2起主要密封,密封齿3起次要密封,密封齿1起抗拉脱作用。 展开更多
关键词 金属挤压接头 单边相对挤压量 有限元仿真 接触应力 密封性
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单晶合金激光增材修复接头组织和性能研究
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作者 秦仁耀 周腾 +5 位作者 孙兵兵 陈冰清 曲致奇 张强 高超 张学军 《失效分析与预防》 2024年第1期1-5,共5页
采用激光熔化沉积技术对DD6单晶高温合金进行修复,利用光学显微镜、扫描电镜和显微硬度仪对单晶母材和增材修复接头的组织特征和力学性能进行对比研究。结果表明:激光熔化沉积修复组织为外延生长的定向凝固柱状晶组织,由γ相基体和少量... 采用激光熔化沉积技术对DD6单晶高温合金进行修复,利用光学显微镜、扫描电镜和显微硬度仪对单晶母材和增材修复接头的组织特征和力学性能进行对比研究。结果表明:激光熔化沉积修复组织为外延生长的定向凝固柱状晶组织,由γ相基体和少量晶间MC型碳化物组成;DD6单晶合金基体热影响区微观形貌和物相组成与母材相似,但其γ′相的尺寸(≤0.2μm)更小,且γ′/γ的比例明显降低。经激光熔化沉积修复后,增材修复区的显微硬度可达450~470 HV,显著高于DD6单晶基体,具有更优异的耐磨损性能。 展开更多
关键词 单晶合金 激光熔化沉积 修复接头 组织和性能
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直升机防扭接头金属结构裂纹智能图像监测
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作者 王昆仑 王春德 +1 位作者 郭玲玲 张思奇 《机械制造与自动化》 2024年第1期276-280,共5页
针对定期人工检测直升机防扭接头金属结构细微裂纹弊端明显的问题,设计裂纹自动图像监测方法。构建图像采集模块,在恰当位置采集直升机防扭接头金属结构图像。预处理采集到的图像,利用灰度拉伸法增强图像,通过中值滤波法滤除图像噪声,... 针对定期人工检测直升机防扭接头金属结构细微裂纹弊端明显的问题,设计裂纹自动图像监测方法。构建图像采集模块,在恰当位置采集直升机防扭接头金属结构图像。预处理采集到的图像,利用灰度拉伸法增强图像,通过中值滤波法滤除图像噪声,提升图像清晰度;分别采用改进后OTSU算法和Canny多尺度空间边缘检测算法,判断裂纹并确定最高阈值和最低阈值,获取候选裂纹片段特征;使用张量投票去除提取到的候选裂纹片段特征中的离散点并连接裂纹片段,实现裂纹自动图像监测。实验结果表明:所提方法的图像预处理效果更加理想,提取到的裂纹误差更小,秒帧率更高。 展开更多
关键词 直升机防扭接头 金属结构裂纹 灰度拉伸 双阈值Canny算子 张量投票
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天冬聚脲防水涂料在金属板拼缝处的应用
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作者 肖升强 刘明 +1 位作者 刘成实 陈国红 《中国建筑防水》 2024年第8期38-40,44,共4页
金属板拼缝处的防水处理是金属屋面防水的关键节点之一。本文结合深圳科技馆新馆项目案例,介绍了天冬聚脲防水涂料在金属板拼缝处的应用优势、施工工艺流程以及细部节点处理做法。
关键词 金属板拼缝 天冬聚脲防水涂料 施工工艺流程 细部节点处理
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