Improving the Productivity and Energy Efficiency by a Heat Treatment Method Applied to Aluminum Forged Parts

In industrial applications, hot forging of AA6082 alloy is carried at 480°C. After the hot forging operation parts are cooled down to room temperature and heated again up to 540°C for solution heat treatment and artificially aged. Heating-cooling-heating cycles leads to energy and time loss in production, and have long-termenvironmental and economic impacts. Mass production of aluminum parts for applications in various industries (automotive, aerospace etc.) requires a process with higher productivity. The aim of this study was to provide time and energy efficiency by combining hot forging and solution treatment processes into a single operation. AA6082 billets were forged at 540°C for 7.5, 15 and 30 minutes in order to achieve simultaneous solution treatment. Billets were then water quenched and artificially aged. Mechanical properties (hardness, tensile strength) as well as microstructure of samples were investigated. Required mechanical properties were achieved on the samples forged and treated at 540°C for 15 and 30 minutes

Transient and reversible deformation of metals under low stresses at elevated temperatures

Available from British Library Document Supply Centre- DSC:DXN058549 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

Improving the Productivity and Energy Efficiency by a Heat Treatment Method Applied to Aluminum Forged Parts

In industrial applications, hot forging of AA6082 alloy is carried at 480°C. After the hot forging operation parts are cooled down to room temperature and heated again up to 540°C for solution heat treatment and artificially aged. Heating-cooling-heating cycles leads to energy and time loss in production, and have long-termenvironmental and economic impacts. Mass production of aluminum parts for applications in various industries (automotive, aerospace etc.) requires a process with higher productivity. The aim of this study was to provide time and energy efficiency by combining hot forging and solution treatment processes into a single operation. AA6082 billets were forged at 540°C for 7.5, 15 and 30 minutes in order to achieve simultaneous solution treatment. Billets were then water quenched and artificially aged. Mechanical properties (hardness, tensile strength) as well as microstructure of samples were investigated. Required mechanical properties were achieved on the samples forged and treated at 540°C for 15 and 30 minutes

SURFACE MODIFICATION of Fe-8Si ALLOY by BORONIZING AND ITS CHARACTERIZATION

In this study Fe-Si binary alloy containing 8 at. % Si and pure iron were pack boronised at 900 degrees C, 1000 degrees C and 1100 degrees C for 3 h using Ekabor II powder. The microstructure, chemical composition, phase contents and microhardness of the formed boride coatings were characterized by means of XRD, SEM-EDS and Vickers Microhardness measurements. The saw-tooth morphology was observed on both substrates, it tended coarsen with boriding temperature and especially with the addition of Si to the substrate. Silicon did not dissolve in the boride layer but accumulated between boride layer and Fe-8Si substrate and formed a Si rich transition zone with an average hardness of 500 HV. The average hardness value of the boride layers on both substrates were approximately 2200 HV. The boride layer thickness increased near-linearly with boronizing temperature for both materials. The presence of silicon in the substrate reduced the thickness of boride layer compared to the boride layer thickness on pure iron. The amount of boron rich FeB phase compared to Fe2B phase was higher on the boride layer of Fe-Si alloy than of pure iron

Fabrication and Transport Critical Current Densities of MgB 2

We have fabricated superconducting 6 and 7 filaments $MgB_2//Fe//Cu$ tapes by ex situ powder-in-tube method using Cu-sheath without any intermediate annealing. Properties of two different multicore $MgB_2//Fe//Cu$ tapes annealed at 900C for 2 h in high purity argon gas atmosphere were compared. The samples were characterized using scanning electron microscope, X-ray diffraction, electron dispersive spectroscopy, optical microscopy, critical transition temperature, transport critical current density, and magnetic measurements. Transport critical current densities of the 6 and 7 filaments tapes were found to be 450 A/cm^2 and 190 A/cm^2 at 20 K, respectively. From X-ray diffraction measurements, lattice parameters a and c were determined. From dc resistivity measurements, the connectivity between grains was investigated by using Rowell's connectivity analysis

Fabrication and Transport Critical Current Densities of MgB2//Fe//CuMgB_2//Fe//Cu Multifilament Tapes without Any Intermediate Annealing

We have fabricated superconducting 6 and 7 filaments $MgB_2//Fe//Cu$ tapes by ex situ powder-in-tube method using Cu-sheath without any intermediate annealing. Properties of two different multicore $MgB_2//Fe//Cu$ tapes annealed at 900C for 2 h in high purity argon gas atmosphere were compared. The samples were characterized using scanning electron microscope, X-ray diffraction, electron dispersive spectroscopy, optical microscopy, critical transition temperature, transport critical current density, and magnetic measurements. Transport critical current densities of the 6 and 7 filaments tapes were found to be 450 A/cm^2 and 190 A/cm^2 at 20 K, respectively. From X-ray diffraction measurements, lattice parameters a and c were determined. From dc resistivity measurements, the connectivity between grains was investigated by using Rowell's connectivity analysis

Determination of fungal pathogens of Hypera postica (Gyllenhall) (Coleoptera: Curculionidae): isolation, characterization, and susceptibility

WOS: 000436823500002Background: Fungal pathogens of Hypera postica (Gyllenhall) (Coleoptera: Curculionidae) were collected from the vicinities of Adana and Igdir in Turkey. The pathogenicity of the fungal isolates against the pest were investigated. According to morphologic (colony morphology, spore shape) and molecular (sequences of ITS1-5.8S ITS2 region and EF1-a, Bloc, and RPB1 genes) characterizations, the isolates were identified as Beauveria bassiana (HpI-2, HpI-6, HpI-7, HpI-10, HpA-3, HpA-4, HpA-5) and Beauveria pseudobassiana (HpI-4). All these strains were isolated from H. postica for the first time. In order to determine pathogenesis of all isolates on the target pest, bioassays were conducted against larvae and adults, as screening of (1 x 10(7) conidia/ml) and dose-response (1 x 10(5), 1x10(6), 1 x 10(7), 1x10(8), conidia/ml), under laboratory conditions. The fungal isolates, closely related to each other, yielded significantly varied mortalities on larvae and adults. H. postica larvae were found more susceptible than adults to the fungal isolates in all tests. The highest mortality rates (100 and 98%) for larvae and adults, respectively, were obtained by B. bassiana strain HpA-5 within 14 days at 1 x 10(8) conidia/ml concentration. The median lethal concentration (LD50) of HpA-5 required to kill the larvae and adults of H. postica at concentrations of 2.37 x 10(4) and 1.4 x 10(5) conidia/ml, respectively. These results are promising; therefore, the B. bassiana strain HpA-5 can potentially be used against H. postica

Mg65Ni20Y15-xAgx (X=1, 2, 3, 5) ALLOYS PREPARED VIA ATMOSPHERE CONTROLLED INDUCTION SYSTEM

In this work, Mg65Ni20Y15–XAgX (X = 1, 2, 3, 5) alloys were manufactured by atmosphere controlled induction system. The effect of Ag ratio on the microstructural properties, micro-hardness, density, and homogeneity of the Mg–Ni–Y alloys were investigated. These alloys were characterized by X-ray diffraction (XRD), optical microscopy, scanning electron microscopy with energy dispersive X-ray (SEM-EDX) and Vickers micro-hardness measurement. According to XRD results, Ni3Y and Mg6Ni phases were observed as well as AgY and Ag17Mg54 phases, which were obtained in alloys. The quantitative results of EDX analysis confirm that the chemical composition of the obtained phases is very close and their homogeneities are so high. The average micro-hardness values of the ingot alloys were measured between 208 and 266 HV for matrix. The elastic modulus and densities of the Mg65Ni20Y15–XAgX (X = 1, 2, 3, 5) alloys increased by increasing Ag in the alloys and they were determined in the range of 58.18–68.12 GPa and 3.14–3.53 g/cm3, respectively.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author