scholarly journals Influence of Explosive Ratio on Morphological and Structural Properties of Ti/Al Clads

Metals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 119 ◽  
Author(s):  
Zhonghang Fang ◽  
Changgen Shi ◽  
Hesheng Shi ◽  
Zerui Sun
Keyword(s):  
Ductile Fracture ◽  
Energy Dispersive Spectrometer ◽  
Plate Thickness ◽  
Shear Bands ◽  
Bonding Interface ◽  
Tensile Fracture ◽  
Explosive Cladding ◽  
Bending Performance ◽  
Comprehensive Properties ◽  
Upper Limits

The current work focuses on the effect of explosive ratio R on the comprehensive properties of Ti/Al clads manufactured via explosive welding. The lower and upper limits of explosive ratio, namely R1 and R2, were determined according to the R–δf (flyer plate thickness) welding window. Two TA2/1060 explosive cladding plates were successfully manufactured at the different explosive ratios. Microstructure investigation was conducted by optical microscopy (OM), scanning electron microscopy (SEM), and energy dispersive spectrometer (EDS). The small wave bonding interface was observed at R1, where the vortex structure containing the ingot structure appeared periodically. The bonding interface presented a big wave bonding morphology and a locally continuous melting layer at R2. Many prolonged grains and adiabatic shear bands (ASBs) were found near the interface for a greater explosive load. Intermetallic compounds were formed in the bonding zones of the two plates. The thickness of element diffusion area increased with an increasing explosive ratio. Comparative tests of mechanical properties indicated that the tensile shear strength at R1 was higher. The microhardness, tensile strength, and bending performance of the two plates are similar and acceptable. Tensile fracture analysis indicated the fracture mode at R1 was ductile fracture, while the explosive cladding plate at R2 had mainly ductile fracture with quasi-cleavage fracture as the supplement.

Research on Cladding Nickel on Copper Crystallizer Using Laser Metal Deposition Technique

2010 ◽  
Vol 97-101 ◽  
pp. 3846-3851 ◽  
Author(s):  
Guang Yang ◽  
Wei Jun Liu ◽  
Wei Wang ◽  
Fei Xing ◽  
Feng Jie Tian ◽  
...  
Keyword(s):  
Erosion Resistance ◽  
Energy Dispersive Spectrometer ◽  
Processing Parameters ◽  
Metal Deposition ◽  
Bonding Interface ◽  
Laser Metal Deposition ◽  
Optimal Processing ◽  
Large Numbers ◽  
Nickel Based Alloy ◽  
Cladding Layers

To increase the strength and erosion resistance of Copper Crystallizer, the system based on Laser Metal Deposition (LMD) process was proposed to clad nickel-based alloy on its surface. With the optimal processing parameters ascertained by large numbers of experiments, the crystallizer was clad nickel-based alloy. The morphology and the microstructures of the cladding layers and bonding interface were analyzed by energy dispersive spectrometer and scanning electronic microscopy. The result shows that the bonding interface realizes the metallurgic and tight bonding.

THE SURFACE AND INTERFACE PROPERTIES OF VANADIUM CARBIDE COATING PREPARED BY THERMAL DIFFUSION PROCESS

2011 ◽  
Vol 10 (01) ◽  
pp. 183-190 ◽  
Author(s):  
DEJUN KONG ◽  
CHAOZHENG ZHOU
Keyword(s):  
Thermal Diffusion ◽  
Vanadium Carbide ◽  
Chemical Elements ◽  
Energy Dispersive Spectrometer ◽  
Salt Bath ◽  
Bonding Interface ◽  
Surface And Interface ◽  
Coating Surface ◽  
Bonding Method ◽  
Vanadium Carbide Coating

Vanadium carbide (VC) coating is prepared with Thermal Diffusion (TD) method in the salt bath, and its surface-interface microstructures and energy spectrums were observed with Scanning Electron Microscope (SEM) and Energy Dispersive Spectrometer (EDS), respectively, and the distributions of C , V , Cr , Si , Fe , and Mo in VC coating interface are analyzed. Its interfacial and bonding methods are discussed, and the bonding micromechanism of VC coating in its bonding interface by TD process is analyzed. The experimental results show that the structure of coating surface by TD is single-phase, that is composed of V and C elements, and no other elements, the chemical elements such as V , Cr , C Si , Fe , Mo are the grade distributed in its bonding interface; its bonding method is metallurgical status; microhardness of coating-substrate is the grade distribution, which is direct ratio with the V distribution, microhardness of the coating surface is 3050–3200 HV, and the effect of TD process on roughness of cold-working die surface is little.

Causes and Control Mechanism of Abnormal Structure in the Center of SWRH82B Wire-Rod-Steel

2019 ◽  
Vol 944 ◽  
pp. 294-302
Author(s):  
Lin Lin Liao ◽  
He Wei ◽  
Li Zhang Li ◽  
Yin Li Chen ◽  
Hai Feng Yan ◽  
...  
Keyword(s):  
Cooling Rate ◽  
Heating Temperature ◽  
Energy Dispersive Spectrometer ◽  
Central Area ◽  
Heating Time ◽  
Tensile Fracture ◽  
Air Cooling ◽  
Electron Probe Micro Analyzer ◽  
Segregation Band ◽  
And Control

The cause of drawing fracture of SWRH82B wire rods was analyzed by using optical microscopy, scanning electron microscope - energy dispersive spectrometer and electron probe micro-analyzer - wavelength dispersive spectrometer. A multivariate diffusion model was established in Thermo-Cale, and the effects of temperature and time on diffusion behavior of alloys were studied. Results show that cementite network and martensite in the center area of rod is main cause of tensile fracture. There is serious segregation of chromium and manganese in the central area. The CCT curve moves to right, and critical cooling rate of martensite decreases. With high cooling rate, time for eutectoid transition is insufficient, and martensite transformation occurs in segregation band. The segregation of phosphorus further worsen the brittleness of steel. With increase of heating temperature and duration of heating time, segregation in final product is reduced, and content of cementite network and martensite decreases. When the temperature is maintained at 1050 °C for 600 s, there is no segregation of phosphorus and carbon. The diffusion of chromium is even when temperature is maintained at 1150 °C for 5400 s, and an even diffusion of manganese is obtained when temperature is maintained at 1200 °C for 3000 s. In stelmor air cooling process, the key point is keeping cooling rate low to extend holding time, and to optimize microstructure and properties.

Interactive Failure in High Velocity Impact of Two Box Beams

2003 ◽  
Author(s):  
Liang Xue ◽  
Li Zheng ◽  
Tomasz Wierzbicki
Keyword(s):  
Ductile Fracture ◽  
Initial Phase ◽  
Equivalent Strain ◽  
Tensile Fracture ◽  
Recent Attempt ◽  
Mode Iii ◽  
Plane Shear ◽  
Wide Range ◽  
The Impact ◽  
Element Removal

The research reported in the present paper has been motivated mainly by the need of reconstructing the airplane impact damage of the WTC Towers. The initial phase of this catastrophic event was dominated by fracture, leading to breakup and fragmentation of the airplane and severance of a large number of external columns. However, the role of fracture has been de-emphasized in the recent attempt to reconstruct the 9/11 attack [1–3]. The objective of this paper is to raise the phenomenon of ductile fracture to the level of a main factor controlling the initial phase of the September 11th event. Our philosophy is similar to that employed by Lawver et al [4], but we are treating ductile fracture in a much more comprehensive way including the topics of material testing, calibration, validation and finite element implementation. A particular scenario considered is the impact of a corresponding section of the wing of the Boeing 767 into one external box column of a Twin Tower. Real dimensions are taken for the WTC column and the wing section is represented as a thin-walled box beam. Both members undergo extensive plastic deformation and fracture. In developing computer models, special attention was paid to the choice of the element type (shell vs. solid), contact algorithm, element removal (erosion) option, and above all the fracture criterion. Most calculations were done using LS-DYNA for several combinations of the equivalent strain to fracture of the aluminum alloy wing and the steel columns. In addition five ABAQUS runs were made with a newly developed criterion for ductile fracture with a cut-off value for negative triaxialities. Impact velocities considered ranged from 120 to 480 m/sec where 240 m/sec was the actual impact speed of the Boeing 767. It was found that the damage process is localized in the immediate velocity of the impact area. The fracture process initiates at the impacting flanges in the Mode III out-of-plane shear, continues down the webs as a combined shear/tension (tearing) and finally ends up as a tensile fracture of the rear flanges. While the airplane wing box was almost always completely cut, the WTC column was often partially penetrated for a wide range of the equivalent strain to fracture. It was also found that introducing a modified fracture locus changes the sequence of failure pattern as well as the mode of fracture.

Numerical Analysis of Bearing Capacity to Q690 Tubular Joints Enhanced by Inner Annular Plate

2013 ◽  
Vol 275-277 ◽  
pp. 951-955
Author(s):  
Jun Fen Yang ◽  
Tao Zhang ◽  
Yi Liang Peng ◽  
Hong Bo Li
Keyword(s):  
Bearing Capacity ◽  
Annular Plate ◽  
Plate Thickness ◽  
Local Buckling ◽  
Thickness Variation ◽  
Finite Element Program ◽  
Bending Performance ◽  
Tubular Joints ◽  
Panel Zone ◽  
Element Program

Simple joint is a common connection type in tubular structures. In this joint, one or more tubes are welded directly on the surface of another tube. Local buckling occurs in panel zone when the joint load is heavy, and such local buckling will reduce the bearing capacity and stiffness of the joint. In order to improve bearing capacity of tubular joints, the joint needs to be strengthened. In this paper, the bending performance of the joint will be enhanced by welding two annular plates inside the surface of panel zone of chord member. By ANSYS finite element program, the bearing capacity of the joint with different inner annular plate was analyzed, including design bearing capacity and ultimate bearing capacity. The results showed that comparing to annular plate thickness variation, the width variation and interval variation have much more influence on the bearing capacity of the joint.

scholarly journals Dissimilar welding of aluminum alloys 2024 T3 and 7075 T6 by TIG process with double tungsten electrodes

2021 ◽  
Author(s):  
Liamine Kaba ◽  
Mohammed Elamine Djeghlal ◽  
Seddik Ouallam ◽  
Sami Kahla
Keyword(s):  
Energy Dispersive Spectrometer ◽  
Welding Process ◽  
Dissimilar Welding ◽  
Tensile Fracture ◽  
Welding Parameters ◽  
Brittle Strength ◽  
Tungsten Electrodes ◽  
Arc Welding Process ◽  
7075 Alloy ◽  
Structural Hardening

Abstract The aim of this work is to study the metallurgical and mechanical properties of dissimilar assemblies of 2024 T3 and 7075 T6 structural hardening aluminum alloy by TIG twine electrode arc welding process. It will include a weld performed according to optimized welding parameters followed by a study of the macroscopic and microscopic evolution of the dissimilar assembly (2024–7075) using optical and scanning electron microscopy (SEM); In addition, the phase compositions were analyzed with an energy dispersive spectrometer (EDS). Tensile and microhardness tests were performed. The tensile fracture was observed by SEM. We have found that this process thins the weld bead and reduces the size of the heat affected zone (HAZ) of the welded joint. The microhardness is lower in the melted area and higher on the side of the area affected by the heat especially for 7075 alloy, resulting in brittle strength and a sudden drop in breaking strength.

A Study on Weldability of Aluminum Alloy-Aluminum-Steel Transition Joints

2013 ◽  
Vol 631-632 ◽  
pp. 713-716 ◽  
Author(s):  
Jian Min Wang ◽  
Yan Zhang
Keyword(s):  
Shear Strength ◽  
Aluminum Alloy ◽  
Explosive Welding ◽  
Marked Change ◽  
Bonding Interface ◽  
Interface Bonding ◽  
Explosive Cladding ◽  
Remarkable Effect ◽  
Welding Technology ◽  
Bonding Properties

Aluminum alloy-aluminum-steel cladding plates were manufactured by explosive welding. Microstructures of the cladding plates were observed and the interface bonding properties were tested. Aluminum alloy-aluminum-steel transition joints were produced by welding the explosive cladding plates. The bonding interface configuration and property were investigated and tested after welding. The effects of welding technology on the interface bonding properties were discussed. The results showed that metallurgical behavior has been occurred at the bonding interfaces between aluminum alloy and aluminum and aluminum and steel. Regular sine waves have appeared on the bonding interface between aluminum alloy and aluminum. However, the bonding interfaces between aluminum and steel present line-shape. The shear strength and separate strength of the cladding plates were much higher than the standard strength. After being welded, the configuration of the bonding interface has no marked change. The strength of the bonding interface decrease a little. The welding technology had no remarkable effect on the bonding interface of the aluminum alloy-aluminum-steel cladding plates.

Influence of particle size on vertical plate penetration into dense cohesionless granular materials (large-scale DEM simulation using real particle size)

2019 ◽  
Vol 21 (4) ◽  
Author(s):  
Shinichiro Miyai ◽  
Murino Kobayakawa ◽  
Takuya Tsuji ◽  
Toshitsugu Tanaka
Keyword(s):  
Particle Size ◽  
Granular Materials ◽  
Vertical Plate ◽  
Plate Thickness ◽  
Shear Bands ◽  
Penetration Resistance ◽  
Packing Fraction ◽  
Size Ratio ◽  
Two Dimensional ◽  
The Mean

Abstract The influence of the particle size on the vertical plate penetration into dense cohesionless granular materials was numerically investigated. Simulations were performed in quasi-two-dimensional conditions by changing the mean particle diameters d50 but maintaining the plate thickness B from B/d50 = 63–2.6. The initial bulk packing fraction was kept high, irrespective of the particle size. In the smallest particle size case (B/d50 = 63), the size ratio reached almost the same level as that in the laboratory experiments using natural sand particles. The results demonstrated that the mean penetration resistance force acting on the plate tip surface increases with a decrease of B/d50, while the tangential force acting on the side surfaces does not change with B/d50. Tip resistances increase linearly with the penetration depth, while the tangential resistances increase with the square of the depth regardless of B/d50. The behavior of the resistance fluctuations changes qualitatively between B/d50 = 31 and 21. For all cases, we confirmed the formation of a wedge-shaped flow with a high forward velocity in front of the plate tip. The wedge flow width was larger than the plate thickness by almost a mean particle diameter, and was responsible for the increase in the mean resistance depending on the particle size. For the large B/d50 cases only, the resistance exhibited quasi-periodic fluctuations, which was attributable to the intermittent nucleation and disappearance of the shear bands. Moreover, we investigated the dependence of B/d50 on the band evolutions by analyzing the band thickness. Graphic abstract The influence of the particle size on the vertical plate penetration into dense cohesionless granular materials was numerically investigated using DEM. Simulations were performed in quasi-two-dimensional conditions by changing the median particle diameters d50 but maintaining the plate thickness B. The initial bulk packing fraction was kept high, irrespective of the particle size. Upper and lower figures show the result of small (B/d50 = 63) and large particle size case (B/d50 = 21), respectively. In the small particle size case (B/d50 = 63), the size ratio reached almost the same level as that in the laboratory and the dynamics of 35.5 million particles was considered. Right and left figures illustrate instantaneous shear strain rate and local packing fraction distributions, respectively. Large qualitative change in the granular behaviors as well as penetration resistance was observed between B/d50 = 31 and 21. The intermittent nucleation and disappearance of the shear bands were clearly observed only for large B/d50 cases.

Sign in / Sign up

Export Citation Format

Share Document