Journal of Materials Research and Technology

Experimental studies using a substantial number of datasets can be avoided by employing efficient methods to predict the mechanical properties of construction materials. The correlation between the mechanical attributes and structural performance of these structures can be determined using an efficient mathematical model.

Corrosion rate data using NOVA 2.1.1 software. EDS data using Scanning electron microscope (SEM) JEOL JSM – IT100 (LA)

1. The yield strength, tensile strength and elongation are measured by tensile test. 2. The equivalent circuit of galvanic corrosion are fitting by the software of ZSimDemo. When the equivalent circuit diagram (R(CR(CR))) is used, the data error under all conditions is less than 5%. The fitting data are listed in table 3. 3. The corroded surface morphologies are testing by TESCAN VEGA III, the microstructure of the intragranular precipitates and precipitates in the grain boundary are showing by JEOL-2100F.

Fig.1. Schematic of the tri-arc twin wire welding process Fig. 2. Tri-arc twin wire welding current waveform Fig. 3. High-speed video photographs at 30 V Fig. 4. High-speed video photographs at 35 V Fig. 5. High-speed video photographs at 40 V Fig. 6. The Lorentz force in tri-arc twin wire arc welding Fig. 7. The major forces acting on the droplet in three arc double wire arc welding Fig. 8. Major forces acting on the droplet in tri-arc twin wire arc welding process Fig. 9. Macro appearance of welding bead. Fig. 10 Composite transition particle splash

With the latest developments in the welding technology, newer and more advanced welding processes have been developed, GMAW has been modified to obtain faster deposition. The development trend of welding has gradually changed from single-wire to double-wire and single-arc into multi-arc. These new welding methods have demonstrated significant advantages in terms of deposition rate and welding speed. However, all of them are based on the traditional GMAW principle. During the welding process, the welding wire, the arc, and the work-piece are connected in series. Hence, the welding current in the conventional GMAW is the same for the anode and the cathode. Thus, increasing the welding current to improve the deposition rate would also cause an increase in the base metal heat input, which may lead to welding deformation and weld metal performance degradation. Therefore, in order to improve the welding deposition rate, the traditional GMAW must be changed. Novel a tri-arc twin wire arc welding has been developed to provide an alternative way to increase the deposition rate and obtain a stale welding process. And solve the questions about high deposition rate, low heat input of the twin wires. This study created a tri-arc twin wires welding method that can adjust the current of wire and workpiece. It introduced three arcs between the twin wires and the weld workpiece. The current flowing through the wires and the workpiece were independently controlled by variable polarity power supply and the DC (Direct Current) pulse power supply. The introduction of the M arc changed the distribution of arc energy during the welding process, increase the M arc current could reduce heat input and increase production efficiency.

Effect of melt hydrogenation on microstructure evolution and tensile properties of (TiB+TiC)/Ti-6Al-4V composites

To improve the growth of hydroxyapatite (HA) coating on the Ti–6Al–4V substrate, a solution containing calcium acetate (CA), calcium glycerophosphate hydrate (Ca-GP), and different concentrations of Na2SO4 as the electrolyte for anodic treatment was investigated in this study. The results found that the anodic method is suitable for Ti–6Al–4V titanium alloy to form an HA coating with the electrolyte consisting of CA, Ca-GP, and Na2SO4. These anodic oxide films display a greater rough structure on the surface of films and the addition of Na2SO4 into the electrolyte during the anodic oxidation process contributes to an increase in the atomic ratio (at%) of Ca in the anodic film. These Ca-containing films are considered bioactive and tend to dissolve into simulated body fluid (SBF) solution and then enhance the degree of the supersaturation of SBF solution with respect to the apatite. Therefore, increasing the concentration of Na2SO4 increases the growth of HA following immersion into SBF. In addition, prior to immersion into SBF solution, the contact angle measurement using an SBF droplet was also investigated for HA growth. The results indicate that when the contact angle of anodic surface is larger, the formation time of HA coating is shorter and it will easily grow a thicker HA.

The simulated and measured data in toroidal dipole metamaterials.

marc model

The low-cycle fatigue (LCF) deformation mechanism and fatigue life of an Al-12Si alloy were investigated at different temperatures and strain rates. With increasing temperature, the fatigue life increases at first and then reduces, which is derived from the deformation mechanism. At the lower temperatures, the primary Si cracking induced by piling-up of dislocations dominates fatigue damage behaviors. Both of increasing temperature and reducing the strain-rate can restrain the phase cracking, thus increase fatigue life. However, with further increasing temperature, the micro-scale void caused by dislocation annihilation dominates the phase debonding behavior, leading to the decrease of fatigue life.