Study of fatigue properties for weld HAZ of EH36MOD steel

ＳｔｕｄｙｏｆｆａｔｉｇｕｅｐｒｏｐｅｒｔｉｅｓｆｏｒｗｅｌｄＨＡＺｏｆＥＨ３６ＭＯＤｓｔｅｅｌＣＡＩＨｏｎｇｎｅｎｇ；ＣＨＡＯＴａｎｈｕａ；ＺＨＯＵｌｉｘｉａ；ＹＡＮＧＹｏｎｇｘｉｎｇａｎｄＦＥＩＤｅｃａｉ（ＰｒｏｆＣＡＩＨｏｎｇｎｅｎｇ，Ｓｃｈｏ...     

Analysis on mechanism of axial drifting of cylinder workpiece on welding roller bed

Ａｎａｌｙｓｉｓｏｎｍｅｃｈａｎｉｓｍｏｆａｘｉａｌｄｒｉｆｔｉｎｇｏｆｃｙｌｉｎｄｅｒｗｏｒｋｐｉｅｃｅｏｎｗｅｌｄｉｎｇｒｏｌｌｅｒｂｅｄ￥ＳＨＥＮＦｅｎｇｇａｎｇ；ＰＡＮＸｉｄｅ；ＸＵＥＪｉｎａｎｄＷＡＨＧＺｈｅｎｇ（ＷｅｌｄｉｎｇＲｅｓｅａｒ...     

Mathematical model of oxygen outdiffusion

ＭＡＴＨＥＭＡＴＩＣＡＬＭＯＤＥＬＯＦＯＸＹＧＥＮＯＵＴＤＩＦＦＵＳＩＯＮＯＮＬｉｕＲｏｎｇ；Ｃｈｅｎｇ，ＱｉｕｐｉｎｇＬｉ；ＹｉｄｏｎｇＳｈｅＳｉｍｉｎｇ（ＣｅｎｔｒａｌＳｏｕｔｈＵｎｉｖｅｒｓｉｔｙｏｆＴｅｃｈｏｌｏｇｙＣｈｎｇｓｈａ４１００８３...     

Effects of Cu， Ni， Mn and Mo on the austemperability， microstructures and mechanical properties of ADI weld metal

ＥｆｆｅｃｔｓｏｆＣｕ，Ｎｉ，ＭｎａｎｄＭｏｏｎｔｈｅａｕｓｔｅｍｐｅｒａｂｉｌｉｔｙ，ｍｉｃｒｏｓｔｒｕｃｔｕｒｅｓａｎｄｍｅｃｈａｎｉｃａｌｐｒｏｐｅｒｔｉｅｓｏｆＡＤＩｗｅｌｄｍｅｔａｌＳＵＮＤａｑｉａｎ；ＺＨＯＵＺｈｅｎｆｅｎｇａｎｄＲＥＮＺ...     

TXD as selective depressand of fluorite and calcite

ＴＸＤＡＳＳＥＬＥＣＴＩＶＥＤＥＰＲＥＳＳＡＮＴＯＦＦＬＵＯＲＩＴＥＡＮＤＣＡＬＣＩＴＥＴｉａｎ，Ｘｕｅｄａ；Ｚｈｕ，Ｊｉａｎｇｕａｎｇ（ＤｅｐａｒｔｍｅｎｔｏｆＭｉｎｅｒａｌＰｒｏｃｅｓｓｉｎｇＥｎｇｉｎｅｅｒｉｎｇ，ＣｅｎｔｒａｌＳｏｕｔｈＵｎｉ...     

U.S. Department of Energy Research in Intermetallic Alloys and Composites

Ｕ．Ｓ．Ａ．Ｕ．Ｓ．ＤｅｐａｒｔｍｅｎｔｏｆＥｎｅｒｇｙＲｅｓｅａｒｃｈｉｎＩｎｔｅｒｍｅｔａｌｌｉｃＡｌｌｏｙｓａｎｄＣｏｍｐｏｓｉｔｅｓ￥ＡｌａｎＬ．Ｄｒａｇｏｏ（ＤｉｖｉｓｉｏｎｏｆＭａｔｅｒｉａｌｓＳｃｉｅｎｃｅｓＯｆｆｉｃｅｏｆＢａｓｉｃＥ...     

Design and development of automatic systems for assembly welding muffler of Santana automobile

ＤｅｓｉｇｎａｎｄｄｅｖｅｌｏｐｍｅｎｔｏｆａｕｔｏｍａｔｉｃｓｙｓｔｅｍｓｆｏｒａｓｓｅｍｂｌｙｗｅｌｄｉｎｇｍｕｆｆｌｅｒｏｆＳａｎｔａｎａａｕｔｏｍｏｂｉｌｅＨＥＤｅｆｕ；ＹＵｈａｉｌｉａｎｇ；ＴＡＮＧＸｉｎｈｕａ；ＷＡＮＧＳｉｚｕｏａｎｄＺｈ...     

Microstructures and properties of molybdenum wires doped with La

ＭＩＣＲＯＳＴＲＵＣＴＵＲＥＳＡＮＤＰＲＯＰＥＲＴＩＥＳＯＦＭＯＬＹＢＤＥＮＵＭＷＩＲＥＳＤＯＰＥＤＷＩＴＨＬａＺｈｏｕ，Ｍｅｉｌｉｎｇ；Ｌｉ，Ｊｕｎ；Ｚｕｏ，Ｔｉｅｙｏｎｇ（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｅｒｉａｌｓＳｃｉｅｎｃｅａｎｄＥｎｇｉｎｅ...     

FRACTURE MECHANISM IN Ti_3Al Si Nb ALLOYS

ＦＲＡＣＴＵＲＥＭＥＣＨＡＮＩＳＭＩＮＴｉ_３Ａｌ＋Ｓｉ＋ＮｂＡＬＬＯＹＳＷＵＪｉａｎｓｈｅｎｇ；ＺＨＡＮＧＬａｎｔｉｎｇ；ＱＩＵＧｕｏｈｕａ（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｅｒｉａｌｓＳｃｉｅｎｃｅ，ＳｈａｎｇｈａｉＪｉａｏＴｏｎｇＵｎｉｖｅｒｓｉ?..     

Adsorption effect mechanism of sodium oleate on feldspar and quartz

ＡＤＳＯＲＰＴＩＯＮＥＦＦＥＣＴＭＥＣＨＡＮＩＳＭＯＦＳＯＤＩＵＭＯＬＥＡＴＥＯＮＦＥＬＤＳＰＡＲＡＮＤＱＵＡＲＴＺＬｉｕ，Ｙａｃｈｕａｎ；Ｇｏｎｇ，Ｈｕａｎｇａｏ（ＭｉｎｅｒａｌＥｎｇｉｎｅｅｒｉｎｇＤｅｐａｒｔｍｅｎｔ，ＮｏｒｔｈｅａｓｔｅｎＵｎ...     

Corrosion resistance of TiO2 films grown on stainless steel by atomic layer deposition

Titanium dioxide (TiO₂) films have been deposited onto stainless steel substrates using atomic layer deposition (ALD) technique. Composition analysis shows that the films shield the substrates entirely. The TiO₂ films are amorphous in structure as characterized by X-ray diffraction. The electrochemical measurements show that the equilibrium corrosion potential positively shifts from − 0.96 eV for bare stainless steel to − 0.63 eV for TiO₂ coated stainless steel, and the corrosion current density decreases from 7.0 × 10^− 7 A/cm² to 6.3 × 10^− 8 A/cm². The corrosion resistance obtained by fitting the impedance spectra also reveals that the TiO₂ films provide good protection for stainless steel against corrosion in sodium chloride solution. The above results indicate that TiO₂ films deposited by ALD are effective in protecting stainless steel from corrosion.     

A new type of pilot arc power source used for A．C． plasma arc welding of aluminum alloys

ＡｎｅｗｔｙｐｅｏｆｐｉｌｏｔａｒｃｐｏｗｅｒｓｏｕｒｃｅｕｓｅｄｆｏｒＡ．Ｃ．ｐｌａｓｍａａｒｃｗｅｌｄｉｎｇｏｆａｌｕｍｉｎｕｍａｌｌｏｙｓ￥ＺｈｅｎｇＢｉｎｇ；ＷａｎｇＱｉｌｏｎｇａｎｄＬｉＸｉａ（ＨａｒｂｉｎＩｎｓｔｉｔｕｔｅｏｆＴｅｃｈｎｏ...     

Improvement in corrosion resistance of CrN coated stainless steel by conformal TiO2 deposition

A conformal titanium dioxide (TiO₂) layer was deposited onto chromium nitride (CrN) coated stainless steel by atomic layer deposition technique, and the electrochemical corrosion test on the CrN single-layer and TiO₂/CrN double-layer coated sample was carried out. The equilibrium corrosion potential of the double-layer coated sample shifted positively compare to that of the single-layer coated one. Moreover, the corrosion current density decreased significantly with the TiO₂ deposition, revealing that better corrosion resistance was obtained after the deposition of the TiO₂ layer. The improvement in corrosion resistance after the TiO₂ deposition was attributed to the blocking of the through-thickness cracks or pinholes in the CrN layer.     

Influence of pre-treatment on the surface composition of Al-Zn alloys

The influences of pre-treatments on the composition of Al-Zn alloys, containing 0.6-1.9 at.%Zn, are investigated using scanning and transmission electron microscopies, glow discharge optical emission spectroscopy and ion beam analysis. Alkaline etching, anodic alkaline etching and electropolishing result in zinc enrichments, just beneath the oxide/hydroxide films on the alloy surfaces. The enriched alloy, about 4-5 nm thick, contains zinc in solid-solution with aluminium, up to about 18 at.%. The highest and lowest enrichments are produced by alkaline etching and electropolishing respectively. For a given pre-treatment, the enrichment increases with increase in zinc content of the bulk alloy.     

Optimization of transparent conducting oxide ZnO compound thickness in terms of four alloys thermo-physical performance aggregates

ZnO is one of the well-known metal oxide semiconductors, which has been found, in the last four decades, to be very useful as transparent conductors and UV detectors in optoelectronic devices. This binary compound that showed quantum confinement effects in accessible size ranges was elaborated using several techniques. In the present work, the sprayed pyrolysis technique was carried out to prepare undoped ZnO crystals with different controlled thicknesses.Particularly, and parallel to recently performed measurements, a recently proposed range of optimal layer thickness d is validated, through original conjoint morphological-structural-physical investigations.     

Atomistic simulations of the characteristics of TiSiN nanocomposites of various compositions

We performed classical molecular dynamics simulations of thermodynamically preferred structures of Ti_(50-x)Si_xN₅₀ (x ≤ 0.3) nanocomposites of various compositions containing up to a quarter of million of atoms. We focus on the formation and growth of TiN nanocrystals, and investigate how the Si content affects their number, size distribution, Si content in them, and thickness of the amorphous phase between them. We observe 3 important cases, namely frequent formation of large crystals below 3% of Si, formation of fine nanocrystalline structures (with quantitatively correct experimental crystal size) around 7% of Si, and amorphization at and above 15% of Si. The results represent the first attempt to predict the structure of TiSiN or similar nanocomposite systems using classical molecular dynamics simulations, and they are compared with experimental measurements of material hardness and electrical resistivity.     

Effect of small amounts of alloyed tin on the electrochemical behaviour of aluminium in sodium chloride solution

Binary model AlSn alloys containing 30–1000 ppm (by weight) Sn were investigated by electrochemical polarization in 5 wt% chloride solution and subsequent characterization of corrosion morphology. In the homogenized and rolled condition, tin concentration only slightly affected electrochemical behaviour up to 500 ppm, and the pitting potentials were all about −0.8 V_SCE. However, alloy containing 1000 ppm Sn was significantly activated by lowering of the passivity-breakdown potential to −1.38 V_SCE. Annealing at 300 °C caused significant segregation of Sn to the metal surface, and all specimens, independent of bulk Sn concentration, became nearly similarly active with breakdown potentials around −1.2 V_SCE. Corrosion on 300 °C-annealed specimens was uniformly distributed by polarization below the bulk pitting potential of −0.76 V_SCE. Moreover, the activation effect was temporary, and corrosion was significantly reduced as the segregated Sn was etched away from the surface. Thick oxide, formed during water quenching on high Sn concentration samples, containing 500 and 1000 ppm Sn, introduced partial passivation during polarization test. Annealing at 600 °C caused increasing activation with increasing Sn concentration, caused by Sn enrichment at the metal surface by dealloying of aluminium during anodic polarization in chloride solution. Corrosion was localized in the form of grain boundary corrosion for alloyed Sn concentration less than and equal to 500 ppm and pitting following the triple grain boundaries for 1000 ppm.     

Effect of tunneling barrier as spacer on exchange coupling of CoFeB/AlOx/Co trilayer structures

Magnetic tunneling junctions (MTJs) have a sandwiched structure, which comprises a top ferromagnetic (FM1) layer, an insulating tunneling layer (spacer), and a bottom ferromagnetic (FM2) layer. Exchange coupling in MTJs has been extensively widely examined because the effect of spacer thickness on the ferromagnetic spin-coupling can be exploited in read-head sensors, spin-valve structures, and magntoresistance random access memories (MRAMs). In this investigation, MTJs were deposited in the sequence, glass/CoFeB(50 Å)/AlO_x(d)/Co(100 Å), where the thickness of the AlO_x layer d = 12, 17, 22, 26 or 30 Å. Saturation magnetization (M_s) results demonstrate that the exchange coupling strength and coercivity (H_c) can be varied considerably by varying the tunneling barrier AlO_x spacer. The X-ray diffraction patterns (XRD) include a main peak from hexagonal close-packed (HCP) Co with a highly (0 0 2) textured structure at 2θ = 44.7°, and AlO_x and CoFeB are amorphous phases. The full width at half maximum (FWHM) of the Co (0 0 2) peak declines as the AlO_x thickness increases, revealing that the Co layer becomes more crystalline. The magnetic results reveal that the magnetic characteristics are related to the Co crystallinity. The exchange coupling strength increases with AlO_x thickness. The coercivity (H_c) also increases, because the Co crystallinity is eliminated.     

Evolution of surface chemistry and morphology of oxide scale formed during initial stage oxidation of modified 9Cr–1Mo steel

Initial stage oxidation characteristics of the modified 9Cr–1Mo steel in ambient air at 650 °C have been investigated, for exposure times ranging from 5 to 500 h. Oxygen flux from the gas phase causes high initial oxidation rate, but the growth kinetics do not follow parabolic law. In “as-received” condition, binary oxides of Fe and Cr were found as native oxides. Upon oxidation, segregation of Mn resulted in the formation of MnCr₂O₄ along with FeCr₂O₄ and binary oxides of Fe, Cr and Mn. Thus, the initial oxide scale constitutes multiple oxides with delineated interface, unlikely to have a layered structure.     

Effect of cooling rate on oxidation resistance and powder ignition temperature of AM50 alloy with addition of yttrium

This paper focused on the effect of cooling rate on oxidation resistance and ignition temperature (T_i) of AM50 alloy. Y addition of 0.0 wt%, 0.15 wt%, 0.28 wt%, 0.45 wt% and 1.00 wt%, respectively was added to the AM50 alloy. The result showed that the oxidation resistance was directly affected by the microstructure. Rapid solidification (RS) had a positive effect on improving the oxidation resistance. It is noticeable that no Al₂Y intermetallic compound was found in the microstructure after RS. Elemental Y dissolved in the solid solution increased with increasing Y addition after RS. It is confirmed that Y addition dissolved in the solid solution and phase distribution were key factors for improving the oxidation resistance.