The most serious softening area of 6061-T6 aluminum alloy after welding is the welding heat-affected zone,which causes the overall strength of aluminum alloy components to decrease.In order to suppress the softening phenomenon of welded joints,new parameters of DC reverse TIG welding and welding impact experiments were used for strengthening.The impact samples were ana-lyzed using a Vickers hardness tester,scanning electron microscopy,energy spectrum analyzer,and electrochemical workstation.The results show that the softening behavior of the welding heat-affected zone weakens after welding impact,and the size and aggrega-tion degree of G.P zone,Mg2Si,CuAl2 and β phase decrease,and the grains are refined.The corrosion current in the impact zone of the welding heat-affected zone is less than that in the non impact zone,and the Tafel slope is greater than that in the non impact zone,so the corrosion resistance is enhanced.
White edge defect for 5052-H32 aluminum alloy anodizing material is one of the common problems in base material pro-duction,which is also hard to solve.For the white part of 5052-H32,the surface roughness was measured by roughness meter,the microstructure was observed by metallographic microscope,and the morphology and chemical composition were analyzed by SEM.The causes of the white part are analyzed,and verified by the actual production conditions and experiment.The probability of defec-tive roll with white difference in both sides is greatly reduced by improving the storage conditions of coil,rolling oil,cleaning process and annealing process,and the effect is remarkable,which basically solves the influence of white difference on the production process of oxidizing material.
In this paper,the structure,geometric size,interference selection,strength calculation and material selection of flat container are discussed comprehensively through the combination of text,graphics and formulas combining with the production practice.
The effect of various chemical composition,homogenization process,and aging process on the electrical conductivity of 6061T6 aluminum alloy extruded bars was determined.The results showed that by controlling the impurity content and Mg/Si ratio in the alloy,the 6061-T6 extruded bar was prepared by homogenization process at 575℃×8 h and aging process at 195℃×6 h.The tensile strength reached 292 MPa,the yield strength was 272 MPa,the elongation after fracture was 13.5％,the hardness was 106 HB,and the conductivity was 46.08％IACS.The electrical conductivities and mechanical properties meet the user requirements.
The corrosion tests on 6061,6005A,6082,6063,and 6N01 alloy profiles produced in industrial production under different quenching methods were conducted to understand the corrosion levels of each alloy and provide certain guidance for industrial produc-tion.6061 and 6005A alloy profiles exhibit exfoliation corrosion and intergranular eorrosion due to the presence of Cu,6063,6082,and 6N01 alloy profiles exhibit good corrosion performance under different queching conditions.
The defect samples of 7075 aluminum alloy pre-stretched thick plate were analyzed by means of low magnification,fracture and microstructure methods,and the corresponding ingot samples were retrospectively analyzed.The results show that the intensive flaws detected of thick plate are caused by microporosity of ingot.By reducing the hydrogen content of melt and the size and volume fraction of microporosity of ingot,the defects caused by microporosity of ingot can be avoided.
The hook defect of friction stir welding(FSW)is an inherent physical defect caused by material heating and physical distor-tion in the process of FSW.It has great influence on the static and dynamic performance of welded components.Based on the appear-ance and causes of hook defects,the mechanism of forming defects in lap joints by friction stir welding(FSW)is reviewed in this pa-per.The effects of material configuration,welding tool shape and length,welding process parameters on hook defect morphology and size are discussed.The hook defects are briefly described according to the research status.The influence of hook defects on mechanical properties and dynamic crack sensitivity of welded joint is analyzed,and some suggestions are put forward to improve the defect in the future.
Aiming at the high performance requirements of water-cooled motor shell profiles,this article carried out alloy composition matching and online quenching tests to obtain reasonable process parameters,and prepared 6063 alloy water cooled motor shell profiles that meet customer requirements.The test results show that increasing the Mg2Si content and slightly excess Si can ensure that the me-chanical properties of the water cooled motor shell profile meet customer requirements by using a high temperature and low speed ex-trusion process,online air cooling or air mist cooling.Considering the impact of temperature changes on the quenching effect in indus-trial production,it is recommended to use wind fog quenching in summer.
The material line is a major defect of 5052 aluminum alloy anodizing material.Through sampling and analyzing the defects of the alloy product,it is found that the defects are caused by the internal metallurgical quality of the ingot.There are two kinds of de-fects,one is oxide inclusion,the other is titanium boron compound inclusion.According to the result of defect analysis,the mecha-nism of forming the defect is analyzed.The cause is mainly related to the online melt treatment,including the type,amount,quality of the refiner,the use of chlorine in the online degassing device,and the cleaning and maintenance frequency of the online degassing de-vice.
The insertion methodology painted aluminum profile was favored by the market because of its excellent corrosion resis-tance,weather resistance,heat insulation and sound insulation performance.The fluorocarbon paint coating falling off at the edge and corner of the strip,which seriously affects the appearance and performance of the product.Through summarizing and analyzing,adjust-ing the cuving process paint group distribution ratio,and other experimental verifications,the occurrence regulurity and cause of eclye and coruer film falbiny have been clarified The paint curing agent system,paint curing process,paint spraying method,rolling pressure and other aspects were optimized and controlled to solve the problem of film falling off at the edges and corners of the insertion meth-odology paint coating profiles,for reference by peers.
The effects of one-stage aging and three-stage aging processes on the microstructure and properties of 7A56 aluminum al-loy thick plates were studied in this paper.The microstructure and properties of 7A56 aluminum alloy thick plates under different ag-ing processes were characterized by transmission electron microscopy,Brinell hardness tester,metal fracture toughness test machine,thermal difference scanner and multifunctional tensile test machine.The results show that:(1)The one-stage peak aging process of 7A56 aluminum alloy thick plate is 120℃/24h,and the tensile strength and fracture toughness are up to 636MPa and 26.12MPa·m1/2;(2)The three-stage aging process can effectively improve the matching problem of strength and toughness of 7A56 aluminum alloy thick plate.The three-stage aging temper is 120℃/24h+175℃/90min+120℃/24h,and the tensile strength and fracture toughness can reach 626MPa and 31.56MPa·m1/2.
The basic characteristics of aluminum alloy is expounded in the paper.The corrosion resistance of marine aluminum alloy is introduced mainly.And its application in ships and marine engineering is analyzed.The situation of China's shipbuilding industry is in-troduced briefly,and the specific suggestions are put forward for reference.
Using test alloy as material and combining with orthogonal test,the best production process parameters of sill beam products are obtained,and the technical requirements of Volkswagen TL116-N28 are used as the inspection standard of the product.The re-sults show that the extruded profile of the sill beam produced has the best comprehensive performance under the extrusion tempera-ture of 490℃ and the aging system of 175℃/12 h.Its tensile strength is 311.8 MPa,the yield strength is 299.0 MPa,and the elonga-tion after fracture is 11.7％.According to the technical requirements of Volkswagen TL116-N28,the profile was inspected,and its me-chanical properties did not decrease significantly after treatment at 205℃/1 h,and the yield strength was 281 MPa(>265 MPa)after treatment at 150℃/1000 h,and there were no defects such as poor welding,holes and other defects in the low-power microstruc-ture.It shows that the short and long-term thermal stability and macrostructure of the product under the optimal process meet the standard requirements.The material did not crack or deform after the hot melt drilling test processing,and the threaded hole was in-spected qualitatively by qualitatively the torque wrench.
By analyzing the defects of the typical material lines of aluminum alloy sheet,it is clear that the material lines are mainly caused by the rolling elongation of slag inclusions containing Mg,Ti or Si.The material line defects could greatly affect the appearance quality of the final product.By analyzing the sources of slag inclusions containing Mg,Ti or Si,the suppression measures are defined.The defects of material lines can be effectively reduced by selecting appropriate melting casting process,controlling the cleanliness of melt,timely cleaning and maintenance of equipment,selecting appropriate refractory materials,strictly controlling the hot rolling and cold rolling line,and the cleanliness of emulsion and oil products.
The effect of residual temperature rolling reduction on microstructure evolution of Al-Mg-Si alloy with Mg/Si ratio of 1.5 was studied by means of metallography observation,scanning electron microscope and X-ray diffraction.The results show that the grain size becomes smaller and the number of fine equiaxed crystals increases with the increase of the rolling reduction at 370℃.After residual temperature rolling,most grains of the sheet still maintain the columnar dendrite morphology.However,with the increase of the reduction amount,the grain size decreases,the number of fine equiaxed crystals on the edge of the sheet increases,the gas hole and porosity in the heart are partially healed,and the formability of the alloy sheet is significantly improved.It is concluded that the residual temperature rolling can promote the formation of more and finer recrystallization grains,homogenize the alloy structure,and signifi-cantly improve the microstructure properties.
Adding rare earth elements Er and Ce to ZL101A aluminum alloy,the differences in microstructure and mechanical proper-ties between the two rare earth treatmentsare are compared.The results show that:in terms of Al and eutectic Si,the refinement effect of Er is significantly better than that of Ce.The addition of Er can form a finer and dispersed rare earth compound phase in ZL101A aluminum alloy,which greatly improves the mechanical properties of the alloy,ZL101A(Er)alloy has a tensile strength of 188 MPa and an elongation of 6.7%,which is higher than that of ZL101A(Ce)alloy.
介绍了0.006 mm双零铝箔轧制用8079铝合金铸锭的质量要求,分析了大规格8079铝合金扁锭的熔铸难点,从炉料、电解铝液预处理、合金元素控制、熔炼与精炼、晶粒细化、在线除气、在线除渣以及铸造工艺参数确定等方面探讨了大规格8079铝合金扁锭熔铸工艺.熔铸生产结果和用户轧制结果表明,用低液位铸造工艺所生产的大规格8079铝合金扁锭的质量完全满足0.006 mm双零铝箔的轧制要求.
通过拉伸测试和显微组织观察等方法,研究不同退火工艺对高镁铝合金板材组织及性能的影响.结果表明:在330℃温度下箱式退火保温2～12 h,样品发生完全再结晶,且随保温时间延长,延伸率增加,晶粒等轴性改善,塑性变好;在380℃温度下箱式退火保温2～12 h,样品发生同样完全再结晶,但相较于330℃箱式退火,随着保温时间的延长,延伸率增加幅度更小,分析与高温箱式退火导致的晶粒粗大有关;模拟380℃/10 s气垫式快速退火,平均晶粒最小,表现为分布均匀的等轴晶粒组织,同时抗拉强度、屈服强度及延伸率均明显高于箱式炉退火样品.采用气垫式高温短时退火生产的卷材塑性最好.
采用金相显微镜、电位计、EPMA和SWAAT腐蚀试验等手段,研究了三种不同Cu含量的Al-2.4Si-0.2Fe-1.2Mn-1.5Zn合金翅片箔钎焊后的冷凝器接头断面形貌、微观组织、元素扩散、电极电位和耐腐蚀性能.结果表明:对于Al-2.4Si-0.2Fe-1.2Mn-1.5Zn合金翅片箔,Cu含量越高,翅片的钎焊前、后强度也越高,钎焊连接良好,但钎焊后的冷凝器和翅片自身的耐腐蚀性会变差;当Cu含量比较低时,钎焊后的冷凝器有着良好的耐腐蚀性能.
辊底炉作为铝合金中厚板实施热处理的关键设备,其淬火冷却水流量对板型控制至关重要.本文对淬火冷却系统关键部件流量计的在线校准进行了研究.介绍了三种常用校准方法的原理及优缺点.针对辊底炉冷却水系统管道直管段不足,存在紊流现象,不符合便携式超声波流量计安装条件的现状,从原理上分析产生紊流的原因和应对办法.通过在管道的不同位置安装传感器,实现多通道测量,采用测量结果平均化方法以减少流体中紊流带来的影响,从而指导工业生产,提高产品质量.另外还通过对实验数据的分析并结合工作经验,对一些异常数据产生原因进行了研究,并提出了进一步提高校准结果准确性的措施和办法.
