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This paper focuses on optimizing the submerged arc welding encapsulation for domestic steel mills producing bridge stainless steel composite plates. It utilizes a combination of numerical simulation and experimental methods to investigate the changes in temperature field and stress field at the weld joint of the Q370qE/31603 stainless steel composite plate using submerged arc welding. The submerged arc welding of Q370qE/31603 stainless steel composite plate is modeled by the ABAQUS software. The submerged arc welding heat source model is represented by double ellipsoidal heat source model and written in Fortran language. The correctness of the stress field was verified by a layer-by-layer electrolytic polishing method based on the X-ray diffraction method to measure the residual stress at different locations after welding. The simulation and experimental results show that the finite element model is very effective for predicting the temperature and stress of submerged arc welding. By changing the parameters of the submerged arc welding process, the effects of different welding process parameters on the temperature field during the welding process, and the distribution state and pattern of post-weld residual stress were studied. Additionally, the research on the thermo-mechanical coupling for the submerged arc welding process of stainless steel composite plate has been carried out; it was found that there is a strong interaction between temperature and stress fields. The hot rolling tests of the stainless steel composite plates were conducted after welding encapsulation to verify the effectiveness of the submerged arc welding encapsulation model. [ABSTRACT FROM AUTHOR]

Aiming at the problem about misjudging sheet fracture in hydroforming process, the different mechanisms between drawing and hydraulic bulging are analyzed. In this paper, a method to test the forming limit diagram (FLD) based on uniform load in thickness direction is adopted by using laminated plate hydroforming, and the quality of hydroforming process is judged more accurately. By the numerical simulation analysis, the shape of the specimen on five different linear paths is preliminarily determined, and the forming limit diagram of the sheet is obtained under the stretch-compression condition. At the same time, the influence of method of lubrication such as non-lubrication, oil, grease, and thin film on FLD is analyzed. The results show that the first principal strain and the second principal strain increase, and the bulging height decreases with the decrease of friction factor. Among them, the friction factor of thin film is reduced to the lowest. In the process of laminated sheet hydroforming, the thin film lubrication between pieces is more relatively accord with the experimental condition of stretch-compression bulging, and the FLD is more reliable to judge the quality of component formed by hydroforming. [ABSTRACT FROM AUTHOR]

How to improve the bonding ability and quality performance of heterogeneous plates has always been one of the difficult problems in the field of high-performance heterogeneous composite sheet forming and manufacturing. In this paper, a new manufacturing method of heterogeneous clad plate, hard plate rolling clad plate, is proposed. The hot rolling process of Al/Mg/Al composite slab with or without hard plate was studied. The results show that the shear stress in the rolling direction (RD) can be transformed into the compressive stress in the normal direction (ND), and then the welding pressure between different composite layers can be increased. This method can suppress the bending and edge crack defects and significantly improve the shape quality and forming ability. At the same time, through the study of the interface structure of the composite plate, it can be known that the metallurgical bonding can be achieved with a small reduction after adding the hard plate. Two clear layers of Al3Mg2 and Al17Mg12 intermetallic compounds appear at the Al/Mg interface. The thickness of the diffusion layer is significantly larger than that of the traditional hot-rolled clad plate, and the thickness of the diffusion layer can reach 38 μm when the reduction is 60%. The yield strength is 172.3 MPa and the elongation is 21.5%. To sum up, the hot rolling of hard-plate provides a new idea for the forming and manufacturing of high performance heterogeneous composite plate. [ABSTRACT FROM AUTHOR]

Recently, the demand for lightweight multilayered parts in electronics and biomedical fields has been accelerated and shown great interest in understanding the combined effect of multilayered materials. However, these industries are still facing the challenge of developing dissimilar multilayered materials that can be suitable for biomedical applications. In this context, magnesium emerges as a promising biocompatible material used for several biomedical applications. However, the issues related to joining magnesium alloys with other similar materials still need to be solved. Moreover, friction stir additive manufacturing (FSAM) occupies a niche domain for developing or joining biocompatible materials such as magnesium alloys with low weight and high strength. Therefore, the present work highlights the development of a multipurpose three-layered multifunctional laminated composite plate of magnesium-based AZ31B–Zn–Al 1100 through the FSAM route. Microstructural and morphological examinations were carried out by light microscopy and FESEM equipped with EDS analysis and line mapping. Moreover, the grain refinement at the interfaces during the FSAM was also addressed using the electron backscattered diffraction (EBSD) study. Further, investigation on mechanical properties such as tensile test with fractography analysis and microhardness variation at the cross-section of the built-up section has been investigated. Furthermore, the corrosion and tribological analysis was also performed, and a 3D profilometer was used to visualize the corroded and worn-out surfaces. The microstructural results revealed that the average grain size of 6.29 μm at interface AZ31B–Zn and 1.21 μm at interface Zn–Al 1100 occurred, improving the bonding strength and overall properties. The tensile strength has occurred as 171.5 MPa at 15.5% elongation, whereas maximum microhardness is reported as 105 HV at the interface of AZ31B–Zn and 84.6 HV at the interface of Zn–Al 1100. The corrosion rate was calculated as 0.00244 mm/day, and the average coefficients of friction (COF) for both the interfaces, such as AZ31B–Zn and Zn–Al 1100, are 0.309 and 0.212, respectively. [ABSTRACT FROM AUTHOR]

This study investigated the manufacturability of ultra-strength steel-Al plate composite, the punch-cutting performance of these composites and base materials, and the cutting surface properties. Therefore, experimental studies included explosive welding, punching process, and materials characterisations (microstructure and sheared surface image analyses via SEM, hardness and tensile test). In the punching process, five different types of punches were used. Additionally, the load cell was mounted on the punch and connected to the computer by an amplifier and a data acquisition card; the force values corresponding to the processing times were directly monitored, and the data were obtained. Shear process analyses were performed using finite elements. Microstructure and mechanical test results show that the DP1200 steel-Al 1100 aluminium laminated bimetal composite was produced by explosive welding of acceptable quality. The flat punch showed the highest shearing force, and other punches (angled and concave ends) reduced the shearing forces P R2, P V16, P R1, and P 16, respectively. Punches with different cutting-edge forms reduced the shearing force by up to 75%. The sheared surfaces were investigated in detail. Shearing marks were observed on both sides of the bimetal similarly. The punching process force vs time results showed good agreement between modelling and experimental punching values. [ABSTRACT FROM AUTHOR]

The interface characteristics and microstructure formation of TA2-5083 composite plate after explosive welded were studied. Optical microscope and electron microscope were used to analyze the microstructure of intermetallic compounds. Furthermore, ANSYS/AUTODYN was adopted to calculate the characteristics of interface microstructure simulated by the smooth-particle hydrodynamics (SPH) method. The results show that most molten metal in the wave front stays in the wave-waist region. There was a relative velocity difference between the vortex of molten metal and the titanium tissue, resulting in that broken titanium particles being scoured by vortexes. Ti3Al was generated in the vortex, whose antioxidant capacity wound lead to the formation of cracks. Consider soldering in a vacuum environment or adding an intermediate layer to reduce interfacial defects. The temperature of the outer vortex was higher than that of inner vortex, and the vortex has a transition layer of 5 μm, which is thinner than the transition layer of 10 μm between the fly and base plate. The jet of molten metal was mostly composed of aluminum, with the jet velocity of interface reaching 3000 m·s−1 and the interface temperature rising up to 2100 K. Compared with the molten metal in the wave-back vortex, the jet temperature at the interface was higher, resulting in a thicker transition layer at the bonding surface. [ABSTRACT FROM AUTHOR]

The aim of this work is to study the method of explosive welding to produce niobium-steel composite plate, which is used in nuclear industry equipment material manufacturing. The welding parameters were determined by weldability window, and numerical simulation was used to predict the wave shape of the welding interface. The morphology of the interface wave was observed by scanning electron microscope. Measured element distribution near the interface. The experimental samples were investigated using mechanical tests. The results show that the welding parameters optimized by theory and numerical simulation can be used to obtain a niobium-steel composite plate with better welding quality. It can be proved that the welding quality is better by observing the interface wave and testing the mechanical properties; it can be seen that the melting zone of the welding interface is composed of niobium and steel by the composition analysis instrument. The morphology of the welding interface wave is consistent with the numerical simulation results, and the numerical simulation shows the changes of temperature, strain, and stress during the welding process. [ABSTRACT FROM AUTHOR]

Mg/Al laminate composites were prepared at 400 ℃ for 15 min through single-pass rolling with reduction ratio from 10 to 27%. The bonding mechanism of the initial bonding stage under low pressure was studied. Two critical statuses (beginning bonding and complete bonding) are found at the reduction ratio of 14.5% and 21.75%. In this article, the coincidence of the ratio of external force (normal stress) and internal force (electronic force) at the two critical points shows that electrons overcome the potential barriers of Mg and Al respectively and make them move freely to form metal bonds. The free movement of electrons between two metal interfaces forms a metallic bond, which bonds the two metals. The formation of metallic bonds overcomes the classical barrier to achieve electron free motion. The ratio of σMg to σAl (σMg/σAl) is 0.7340, and the ratio of fMg to fAl (fMg/fAl) is 0.7988, where it can be found that the former agrees well with the latter. The good agreement between theory and experiment proves that overcoming the potential barrier plays an important role in the early bonding stage of bimetal composite plates. [ABSTRACT FROM AUTHOR]

Thick steel/aluminum/aluminum-alloy composite plates are one of the key materials connecting steel structures and aluminum alloy structures and have been widely used in the shipbuilding industry and other fields. However, steel/aluminum/aluminum-alloy composite plates with a total thickness of more than 10 mm and a steel layer thickness of more than 5 mm are prone to problems such as inconsistent deformation of component metals and low bonding strength during the rolling process, and cannot be continuously prepared. To solve this problem, this article proposes a two-pass different temperature rolling process for thick steel/aluminum/aluminum-alloy composite plates and conducts research on Q235B steel, 1060 aluminum, and 5083 aluminum alloy as component metals. The results show that the process is reliable. It can prepare Q235B/1060/5083 composite plates with a thickness of 15.65 mm without oxygen protection measures. Meanwhile, the interfacial shear and pull-off strength of the composite plates obtained under different experimental conditions in this article are higher than the requirements of the US military standards MIL-J-24445A and Chinese ship standard CB20091-2012. The composite plates show good performance in 90° and 137° bending tests without obvious defects. Under the best condition, a 1.48 μm interlocking diffusion layer is formed at the steel/aluminum interface of the composite plates, the interfacial shear strength exceeds 70 MPa, and the interfacial pull-off strength exceeds 110 MPa. Finally, according to the experimental results, the reasons for the feasibility of the two-pass different temperature rolling of thick steel/aluminum/aluminum-alloy composite plates are given. [ABSTRACT FROM AUTHOR]

In the current study, we proposed a method of differential temperature rolling with electromagnetic induction heating to prepare Ti/Al composite plates in a protective atmosphere to realize the homogeneous deformation of Ti/Al bonding rolling and improve the interfacial bonding strength of the composite plates. The temperature field required for homogeneous deformation rolling of titanium and aluminum was constructed using finite element simulation by adjusting the parameters of electromagnetic induction heating, which made a temperature difference of about 632 °C between titanium and aluminum, and the temperature of each plate was relatively uniform. The induction heating experiment was designed based on the finite element simulation, and the experiment verified the accuracy of the simulation results. The effects of rolling temperature and reduction rate of homogeneous deformation and bonding strength of Ti/Al composite plates were evaluated by rolling experiments. With the increase of rolling temperature and reduction rate of titanium, when the heating temperature of the Ti plate is 750–850 °C, and the reduction rate is 30%–48%, the reduction rate of Ti plate and Al plate gradually tend to be the same. When the titanium plate and aluminum plate temperature is 850 °C and 188 °C, respectively, with a rolling reduction rate of 48%, the deformation rate of Ti plate and Al plate is 46.8% and 48.6%, respectively. Moreover, the bonding strength of the composite plate reaches 77MPa. [ABSTRACT FROM AUTHOR]