Alloy Tubes Research Articles

Pressure-less joining SiCf/SiC tube and Kovar alloy with AgCuInTi filler: interfacial reactions and mechanical properties

Pressure-less joining SiCf/SiC tube and Kovar alloy with AgCuInTi filler: interfacial reactions and mechanical properties

Fundamental Study of Phased Array Ultrasonic Cavitation Abrasive Flow Polishing Titanium Alloy Tubes.

A new method of machining ultrasonic cavitation abrasive flow based on phase control technology was proposed for improving the machining efficiency of the inner wall of TC4 (Ti-6Al-4V) titanium alloy tubes. According to ultrasonic phase control theory and Hertzian contact theory, a model of ultrasonic abrasive material removal rate under phase control technology was established. Using COMSOL Multiphysics 6.1 software, the phase control deflection effect, acoustic field distribution, and the size of the phase control cavitation domain on the inner wall surface were examined at different transducer frequencies and transducer spacings. The results show that the inner wall polishing has the most excellent effect at a transducer frequency of 21 kHz and spacing of 100 mm. In addition, the phased deflection limit was explored under the optimal parameters, and predictive analyses were performed for voltage control under uniform inner wall polishing. Finally, the effect of processing time on polishing was experimented with, and the results showed that the polishing efficiency was highest from 0 to 30 min and stabilized after 60 min. In addition, the change in surface roughness and material removal of the workpiece were analyzed under the control of the voltage applied, and the experimental results corresponded to the voltage prediction analysis results of the simulation, which proved the viability of phase control abrasive flow polishing for the uniformity of material removal of the inner wall of the tube.

Initial stage of titanium alloy tube billet extrusion: simulation and experiment

Initial stage of titanium alloy tube billet extrusion: simulation and experiment

Comparative Study of Life-Cycle Environmental and Cost Performance of Aluminium Alloy–Concrete Composite Columns

As is widely known, the construction industry is one of the sectors with a large contribution to global carbon emissions. Despite numerous efforts in the construction industry to develop low-carbon materials, there is a limited number of studies quantifying and presenting the overall environmental impact when these materials are applied in a construction project as structural members. To address this gap, this study focuses on assessing the life-cycle performance of novel structural aluminium alloy–concrete composite columns. In this paper, the environmental impacts and economic aspects of a concrete-filled aluminium alloy tubular (CFAT) column and a concrete-filled double-skin aluminium alloy tubular (CFDSAT) column were assessed using life-cycle assessment (LCA) and life-cycle cost analysis (LCCA) approaches, respectively. The cradle-to-grave system boundary is considered for these analyses to cover the entire life-cycle. A concrete-filled steel tubular (CFST) column is also assessed for reference. All columns are designed to have the same load-carrying capacity and, thus, are compared on a level-playing basis. A comparison is also made of the self-weight of these columns. In particular, the self-weight of the CFST column is reduced by around 17% when the steel tube is replaced by an aluminium alloy tube, and decreased by 47% when the double-skin technique is adopted in CFDSAT columns. The LCA results indicate that the CO2 emission of CFST and CFAT is almost the same, which is 21% less than the CFDSAT columns due to the use of high aluminium in the latter. The LCCA results show that the total life-cycle cost of CFAT and CFDSAT columns is around 29% and 14% lower, respectively, than that of the CFST column. Finally, a sensitivity analysis was carried out to evaluate the effects of data and assumptions on the life-cycle performance of the examined columns.

Study the Influence of Impact on the Filled Tube of Aluminum 6082-T6 Alloy by Consideration of Temperature using FEM

In this study, a numerical analysis of the impact behavior of a hollow tube made of aluminum 6082-T6 alloy in accordance with ISO 13314-2011 was conducted using FEM. ANSYS was utilized to execute the simulation procedure utilizing the Explicit Dynamic tool. The geometry of the present study consists of a 900 mm-long tube with a diameter of 60 x 2 mm, which was designed using SpaceClaim in Ansys. The model has meshed with a sweep-type mesh utilizing local coordinates. As a result, quadratic elements were utilized to simulate every impactor effect. The convergence of the mesh was determined in accordance with the equivalent strain analysis. The scope of the inquiry is limited to the mechanical behavior and energy conservation that occurs after the impact technique. The energy that is responsible for each and every sort of energy has been recognized. Instability was observed in both the internal and kinetic energies, with the latter reaching a maximum value of three electro-megajoules. Within each of the three axes, the directional deformation of the tube has been outlined. For a period of forty millimeters, the parallel axis of the impactor has undergone the greatest degree of maximum deformation that it has ever encountered. The equivalent stress, also known as von Mises, was measured in combination with the length of the tube, and it was discovered that it reached its highest point at 450 millimeters at the site of impact with 950 megapascal stresses.

Investigation of damage on FeCr26Ni36Co15W5 alloy reduction furnace tube during service

ABSTRACT The microstructure and mechanical properties of tungsten powder reduction furnace tube are investigated in this work. After service, the lamellar and skeleton-shape primary carbides of FeCr26Ni36Co15W5 alloy coarsened and formed a continuous network, much fine secondary carbide precipitated in the dendrite interior. The tensile strength and ductility of FeCr26Ni36Co15W5 alloy decreased. And, the creep strength of FeCr26Ni36Co15W5 alloy has reached the end of the service life. Meanwhile, the corrosion products were studied by XRD and XRF. It was found that the corrosion products were Na2WO4·2 h2O, Na2CO3·H2O and Cr4Ni15W，and the evaporation of catalyst (Na2CO3) results in a large amount of Na2CO3·H2O in the corrosion products. The hot corrosion mechanism of the reduction furnace tube is Type I hot corrosion.

Microstructural and Textural Evolution of a Zr-Sn-Nb-Fe Alloy Tube During Cold Pilger Rolling

Microstructural and Textural Evolution of a Zr-Sn-Nb-Fe Alloy Tube During Cold Pilger Rolling

TIG welding of in-situ produced syntactic metal foam-filled tubes

Abstract Aluminium matrix double composites were produced via an in-situ pressure infiltration method. AlSi12 alloy matrix with densely packed lightweight expanded clay aggregate particle-filled foam was produced in-situ within AlMgSi0.5 alloy tubes. The attainable size of such double composites is limited; therefore, joining them is required to create larger parts. For the joining of these double composites, the applicability of tungsten inert gas (TIG) welding was tested. TIG welding was found to be applicable to join such composites. Metallurgically sound welded joints were produced. Nevertheless, the TIG welding of metal foam-filled tubes is very challenging and needs experienced welding personnel, and the weld bead was a bulk material, not a foam anymore.

The influence of pre-strain on the microstructure and recovery properties of cold-rolled TiNiFe alloy tube

Abstract In the present work, the influence of pre-strain on the microstructures and recovery properties of cold-rolled TiNiFe shape memory alloy tube are studied by pre-strain system, phase transformation testing system, electron backscattered diffraction (EBSD) and transmission electron microscope (TEM). It is demonstrated that the pre-strain has significant effects on the recovery properties, transformation temperatures, and microstructures of TiNiFe alloy. With the increase of pre-strain, the kernel average misorientation (KAM) value and the dislocation pill-up increase, causing the recovery rate of the TiNiFe alloy decreases linearly, and maximum of recovery strain is 8%. And the reverse martensite transformation start temperature (TRs) increases from -133°C to -105°C and TRf increases from -124°C to -97°C, as the increase of pre-strain.

Texture and bendability evolution mechanism of 6063 aluminum alloy tube formed by free-bending technology employing cross-scale numerical modeling

With the improvement of application requirements, the combination of precise shape and high performance of tube components has become a burning issue. This work investigates the free-bending process of 6063 aluminum alloy tubes using cross-scale numerical modeling. The cross-scale framework integrates macroscopic finite element model (FEM) and crystal plasticity finite element model (CPFEM) through strain history. CPFEM exhibits excellent agreement with the macroscopic FEM and experimental results for both the Mises stress and texture evolution. Predictions indicate that as bending deformation increases, the volume fractions of the initial Cube texture decrease, while the Goss texture component increases. The overall texture strength continuously decreases. Meanwhile, slip mode plays a critical role in texture evolution, causing similar trends in the inner and outer bend regions. Additionally, the findings from the cross-scale simulation accurately predict the detailed texture evolution of the 6063 aluminum alloy tube under various feeding speeds. The development of Goss texture in various forming regions and the formation of substructures within Goss-oriented grains are primary factors contributing to reduced tube formability, which could illustrate the primary mechanisms for variation in tube bendability effectively. The proposed cross-scale method lays the foundation for research on complex spatial tube components as well. Moreover, cross-scale simulation facilitates the prediction of macroscopic deformation and microstructural evolution in critical regions of tube components, allowing for the optimization of bending processes based on cross-scale simulation results.

Effect of strain state on the surface roughening for hydroforming of aluminum alloy tube based on cross-scale numerical modeling

The complex deformation behavior would result in surface roughening such as orange peel defect during the hydroforming process of aluminum alloy tubular parts. In order to control the surface quality of hydroformed tubular parts, the effect of strain state on the surface roughening for 2219 aluminum alloy tube was analyzed based on a cross-scale model. The model combined the crystal plasticity model and macroscopic finite element model. During the uniaxial tension, the surface morphology reveals an equiaxed pattern characteristic of orange peel due to the strain incompatibilities between grains, and the peak and valley are stretched along the tensile direction. The surface roughness under tension-compression plane strain state is the lowest due to the low through-thickness strain. In the biaxial tension region, the change rate of surface roughness gradually increases with the decrease of the second principal strain especially in the late deformation stage, and the surface features evolve from an orange peel pattern to a ridging pattern. The forming limit diagram under different strain states based on surface roughness was established to guide the optimization of hydroforming process. Compared with the one-step hydroforming, the surface roughness of the bulging peak of 2219 aluminum alloy tube using multi-step hydroforming with the axial self-feeding decreases obviously from 16.3 to 10.8 μm due to the significant reduction of the equivalent strain.

Growth of α-Al2O3 layer involving abnormal oxides in FeCrAl alloy tube fabricated by WEDM process and electrical insulating performance in fusion reactor blanket

The tubular specimens of FeCrAl alloy APMT (Fe-22Cr-5Al-3Mo) were fabricated by a wire electrical discharge machining (WEDM) process. The oxidation characteristics of the machined surface were investigated by means of the oxidation tests performed in air atmosphere at the temperatures of 1273 K and 1373 K up to 100 h. The abnormal oxides such as CuAl2O4 and ZnAl2O4 were grew on the recast layer which was locally remained on the machined surface even after the mechanical polishing procedure. The α-Al2O3 layer involving the abnormal oxides was formed on the machined surface in the oxidation treatment at 1273 K for 10 h. The apparent electrical conductivity of the layer involving the abnormal oxides was larger than that without the abnormal oxides. Thick Al-rich oxide layer was formed under the abnormal oxides when the oxidation treatment was performed at 1373 K. The apparent electrical conductivity of the oxide layer became lower due to the presence of the thick Al-rich oxide. This oxide layer formed at 1373 K could function as an electrical insulating layer to reduce the magnetohydrodynamic pressure drop in liquid breeder blanket systems of magnetic confinement fusion reactors.

Structural integrity assessment of CANDU pressure tubes using Sobol indices for global sensitivity analysis

CANDU11CANDU is a registered trademark of Atomic Energy of Canada Limited. reactors are a channel-type design where up to 480 zirconium alloy pressure tubes (PTs) act as the reactor pressure boundary. Fitness-for-service standards such as CSA N285.8 (CSA Group, 2015) have been established to prescribe the requirements of pressure tube evaluations to maintain their integrity throughout their lifetime. Probabilistic leak-before-break (LBB) assessments can be used in evaluations to demonstrate that the likelihood of a flaw growing past the stability point while undetected (or before a safe shutdown can be achieved) is below regulatory limits. The assessments typically require a ranking of model parameters based on their influence. The ranking process traditionally uses expert judgment and local sensitivity analysis methods. There has been recent interest in implementing global methods for LBB assessments as they can manage large numbers of variables and extensive sampling spaces. However, their adoption is hindered by the computational cost of the models involved.The current study proposes a method for performing global sensitivity parameter rankings during probabilistic LBB assessments. The study is the continuation of the CANDU nuclear power plant (NPP) pressure tube (PT) case study in El Bouzidi et al., (2024) where a probabilistic approach was implemented in RAVEN (Rabiti and Alfonsi, 2019) to estimate whether the probability of unstable crack growth in PTs is within acceptable limits. This follow-up work proposes surrogate modeling using a high-dimensional model representation to derive Sobol indices and establish a parameter influence ranking. The methodology is demonstrated in a Monte Carlo simulation campaign of a pressure tube inlet rolled joint. The implemented approach successfully identified and quantified critical parameters of the model while efficiently ranking and quantifying the interactions between input variables.

Impact and tangential composite fretting wear of Zr-4 alloy tubes under random loading conditions

The fuel rod casing tube is a crucial component in pressurized water reactor (PWR) nuclear power plants. Flow-induced vibrations in the circulating water can result in complex alternating fretting wear between the casing tube and the positioning lattice frame. Existing research on fretting wear has primarily focused on unidirectional wear, with limited investigation into composite fretting wear under complex working conditions. This study conducted impact and tangential composite fretting wear tests on Zr-4 alloy tubes under varying constant and random impact loads to examine fretting wear behavior. The findings show that the peak friction coefficients in the impact and tangential composite fretting wear tests were consistent across the three constant load conditions, with higher peak friction coefficients observed under random load conditions and a longer time required to reach these peaks during micromotion tests. Comparative analysis revealed that random impact and tangential composite fretting wear caused the most severe damage. Under constant load conditions, wear damage became more severe with increasing load, transitioning from oxidized and adhesive wear to a peeling layer as the load intensified in the impact and tangential composite fretting wear tests.

A novel method to establish friction coefficient model for numerical simulation of inertia friction welding

The precise friction coefficient at interface determines the friction behavior in inertia friction welding (IFW), its model is the basis to precisely describe the friction behavior in the numerical simulation of IFW. To measure the friction coefficient related to the temperature, pressure, and sliding velocity, the IFW trials between 2219-O Al alloy and 304 stainless steel were conducted with the simultaneous measurement of temperature and angular velocity evolutions. Two types of friction coefficient models were established by considering whether the effects of temperature and friction pressure were independent. The S-(T&P) L model, which considered the couple effect of temperature and friction pressure, was recommended as the best suitable model with its very high accuracy and best simplicity. The proposed model was successfully used in simulating the temperature evolution of IFW between Al alloy and steel tubes. The effect of the influencing variables on the friction coefficient was also discussed.

Effects of high-temperature and high-pressure immersion corrosion durations on the fretting tribo-corrosion behaviors of Inconel 690 alloy

An Inconel 690 alloy tube acting as a steam generator tube has been widely applied in the second and third generations of nuclear power plants using pressurized water reactors. However, its entire service process is always accompanied by high-temperature and high-pressure (HTHP) liquid medium corrosion and various fretting mechanical damage behaviors. This study first immerses the Inconel 690 alloy tube in HTHP corrosive medium for different lengths of time (0, 4, 8, and 12 h); then, a fretting tribo-corrosion test rig is used to investigate the effect of different fretting mechanical parameters on the surface damage mechanism and electrochemical dynamic response of each test sample. Results show that the corrosion rate of the Inconel 690 alloy tube has significantly increased after being treated by HTHP immersion corrosion, which is mainly due to the pre-existing corrosion products.

Metallurgical developments in steam-methane reformer tube alloys

Metallurgical developments in steam-methane reformer tube alloys

Ultrasonic-Assisted Granular Medium Forming of Aluminum Alloy 6063-T5: Simulations and Experiments

To address the challenges posed by the complex shapes of hollow parts, this study examined the ultrasonic-assisted granular medium hydroforming (UGMF) process for tubular components. The dynamics of the deformation behavior and deformation control during 6063-T5 aluminum alloy tube free forming by UGMF were studied via simulations and experiments. Based on the ABAQUS software platform, a coupled method based on finite element (FE) simulation analysis and discrete element (DE) analysis for the UGMF free forming process was used. The results showed that ultrasonic vibration (UV) could reduce the forming force required for expansion and promote the flow of material at the end to the forming area as well as inhibit the decrease in the wall thickness. The accuracy of the FE-DE coupled simulation model and a parabolic geometric model was verified by testing. The results found that UV enhances material flow, decreases the forming force needed, and minimizes damage to the granular surface.

Research on AZ31 magnesium alloy tee joint tube with lateral hole by hot extrusion forming with sand mandrel limited by stainless steel gasket

As one of the lightest metals in the world, magnesium alloy can be used to reduce weight and save energy. Magnesium alloy tubes with different shapes can also further direct the transportation of fluid in this light weight. But the tee joint tube is difficult formed because of the complex shapes. In this paper, magnesium alloy tube is applied to form tee joint tube with sand mandrel. During the deformation, the magnesium alloy tube is driven by the sand mandrel pressed by the push. Different from traditional extruding with full tubes without hole on the sidewall, some tube with holes on the sidewalls are also used in the extrusion. All the key parameters such as extrusion depth, temperature, tube length, hole size, and hole location are discussed in both simulations and experiments. After the extrusion results are obtained, the microhardness and microstructures are observed to explain the promotion of the mechanical properties. Based on the results received from both simulations and experiments, deeper extrusion depth, higher temperature, shorter length of tube, larger size of the hole, and the higher location of the hole influence positively on forming results. No matter there are holes or not on the sidewalls, the errors between the results in simulation and experiment are small. Also the simulation and experiment results can be used to investigate the shape of tee joint tubes. The surface quality can be also measured to prove the surfaces in extrusion with sand mandrel acceptable. A novel strategy to sand mandrel extrusion of magnesium alloy tee joint tube by tube with holes on sidewall is provided.

Study on microstructure evolution mechanism and inhomogeneous characteristic of 2219 aluminum alloy in hot flow forming

In order to reveal the evolution mechanism of the deformation microstructure of 2219 aluminum alloy tube under compression-shear stress, in this paper, flow forming tests and their numerical simulations were carried out, respectively, at temperatures from 250 °C to 400 °C. Meanwhile, a midrange layer index was proposed to analyze the gradient of deformation microstructure. The results show that multiple recrystallization mechanisms of the 2219 aluminum alloy are presented simultaneously during hot flow forming. The shear stress during forming is the main factor that generated the microstructure gradient along the thickness direction, and the recrystallization level is higher with higher shear strain. In addition, it is beneficial to improve microstructure homogeneity and mechanical properties by increasing thickness reduction or decreasing the temperature. This study provides guidance for microstructure control of the 2219 aluminum alloy tube flow forming process.