The Experts below are selected from a list of 315 Experts worldwide ranked by ideXlab platform
Pranav Shrotriya - One of the best experts on this subject based on the ideXlab platform.
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hybrid co2 laser waterjet heat lwh treatment of bindered boron nitride composites with Hardness improvement
Ceramics International, 2017Co-Authors: Jingnan Zhao, Kwang Shiong Wong, Pranav ShrotriyaAbstract:Abstract Boron nitride (BN) material is chemically and thermally stable which makes it desirable for high speed machining in demanding chemical and thermal environments. Although the Hardness of BN material is well below that of single polycrystalline diamond (PCD), a laser waterjet heat (LWH) treatment process provides a new potential approach to achieve Hardness values that are comparable to diamond Hardness. This study investigates the Hardness change of LWH-treated bindered cBN/TiN and cBN/AlN composites. Results indicate that measured Hardness Increase is dependent on the laser beam pass and the distance from the beam center.
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Increase the Hardness of polycrystalline cubic/wurtzite boron nitride composite through hybrid laser/waterjet heat (LWH) treatment
Advances in Applied Ceramics, 2017Co-Authors: Jingnan Zhao, Pranav ShrotriyaAbstract:ABSTRACTThe material, boron nitride (BN), is chemically and thermally stable which is desirable for high-speed machining in demanding chemical and thermal environments. Although BN’s Hardness is lower than that of single polycrystalline diamond, a novel laser/waterjet heat treatment process provides a new approach to Increase the Hardness of the dual-phase 50% cubic and 50% wurtzite (cBN/wBN) composite close to or as high as diamond’s Hardness. Results indicate that experimentally measured Hardness Increase is dependent on the processing parameter such as laser fluence and overlap between heat treatment passes. Statistical analysis is carried out to identify the processing parameter that result in maximum Hardness Increase.
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Increase the Hardness of polycrystalline cubic wurtzite boron nitride composite through hybrid laser waterjet heat lwh treatment
Advances in Applied Ceramics, 2017Co-Authors: Jingnan Zhao, Pranav ShrotriyaAbstract:ABSTRACTThe material, boron nitride (BN), is chemically and thermally stable which is desirable for high-speed machining in demanding chemical and thermal environments. Although BN’s Hardness is lower than that of single polycrystalline diamond, a novel laser/waterjet heat treatment process provides a new approach to Increase the Hardness of the dual-phase 50% cubic and 50% wurtzite (cBN/wBN) composite close to or as high as diamond’s Hardness. Results indicate that experimentally measured Hardness Increase is dependent on the processing parameter such as laser fluence and overlap between heat treatment passes. Statistical analysis is carried out to identify the processing parameter that result in maximum Hardness Increase.
Andre Paulo Tschiptschin - One of the best experts on this subject based on the ideXlab platform.
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microstructure and mechanical properties of friction stir welded 8 mm pipe saf 2507 super duplex stainless steel
Journal of materials research and technology, 2019Co-Authors: Rafael Arthur Reghine Giorjao, Victor Ferrinho Pereira, Maysa Terada, Eduardo Bertoni Da Fonseca, Ricardo Reppold Marinho, Diego Martins Garcia, Andre Paulo TschiptschinAbstract:Abstract The microstructure and mechanical properties of 8-mm-thick friction stir welded SAF 2507 super duplex stainless steel pipe was examined. High-quality welds were successfully produced using polycrystalline cubic boron nitride (PCBN) tool, force control mode of 38 kN, travel speed of 50 mm/min, rotational speed of 200 rpm. Hardness and tensile tests were performed, showing Hardness Increase in the stir zone and failure on the base metal. Thermal simulation showed maximum global temperatures around 1176 °C, and different thermal cycles along the joint thickness, providing microstructural and mechanical differences along the welded joint.
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Microstructure and mechanical properties of friction stir welded 8 mm pipe SAF 2507 super duplex stainless steel
Elsevier, 2019Co-Authors: Rafael Arthur Reghine Giorjao, Victor Ferrinho Pereira, Maysa Terada, Eduardo Bertoni Da Fonseca, Ricardo Reppold Marinho, Diego Martins Garcia, Andre Paulo TschiptschinAbstract:The microstructure and mechanical properties of 8-mm-thick friction stir welded SAF 2507 super duplex stainless steel pipe was examined. High-quality welds were successfully produced using polycrystalline cubic boron nitride (PCBN) tool, force control mode of 38 kN, travel speed of 50 mm/min, rotational speed of 200 rpm. Hardness and tensile tests were performed, showing Hardness Increase in the stir zone and failure on the base metal. Thermal simulation showed maximum global temperatures around 1176 °C, and different thermal cycles along the joint thickness, providing microstructural and mechanical differences along the welded joint. Keywords: Friction stir welding, 2507 SDSS, Thermal simulatio
Jingnan Zhao - One of the best experts on this subject based on the ideXlab platform.
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hybrid co2 laser waterjet heat lwh treatment of bindered boron nitride composites with Hardness improvement
Ceramics International, 2017Co-Authors: Jingnan Zhao, Kwang Shiong Wong, Pranav ShrotriyaAbstract:Abstract Boron nitride (BN) material is chemically and thermally stable which makes it desirable for high speed machining in demanding chemical and thermal environments. Although the Hardness of BN material is well below that of single polycrystalline diamond (PCD), a laser waterjet heat (LWH) treatment process provides a new potential approach to achieve Hardness values that are comparable to diamond Hardness. This study investigates the Hardness change of LWH-treated bindered cBN/TiN and cBN/AlN composites. Results indicate that measured Hardness Increase is dependent on the laser beam pass and the distance from the beam center.
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Increase the Hardness of polycrystalline cubic/wurtzite boron nitride composite through hybrid laser/waterjet heat (LWH) treatment
Advances in Applied Ceramics, 2017Co-Authors: Jingnan Zhao, Pranav ShrotriyaAbstract:ABSTRACTThe material, boron nitride (BN), is chemically and thermally stable which is desirable for high-speed machining in demanding chemical and thermal environments. Although BN’s Hardness is lower than that of single polycrystalline diamond, a novel laser/waterjet heat treatment process provides a new approach to Increase the Hardness of the dual-phase 50% cubic and 50% wurtzite (cBN/wBN) composite close to or as high as diamond’s Hardness. Results indicate that experimentally measured Hardness Increase is dependent on the processing parameter such as laser fluence and overlap between heat treatment passes. Statistical analysis is carried out to identify the processing parameter that result in maximum Hardness Increase.
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Increase the Hardness of polycrystalline cubic wurtzite boron nitride composite through hybrid laser waterjet heat lwh treatment
Advances in Applied Ceramics, 2017Co-Authors: Jingnan Zhao, Pranav ShrotriyaAbstract:ABSTRACTThe material, boron nitride (BN), is chemically and thermally stable which is desirable for high-speed machining in demanding chemical and thermal environments. Although BN’s Hardness is lower than that of single polycrystalline diamond, a novel laser/waterjet heat treatment process provides a new approach to Increase the Hardness of the dual-phase 50% cubic and 50% wurtzite (cBN/wBN) composite close to or as high as diamond’s Hardness. Results indicate that experimentally measured Hardness Increase is dependent on the processing parameter such as laser fluence and overlap between heat treatment passes. Statistical analysis is carried out to identify the processing parameter that result in maximum Hardness Increase.
Ning Guo - One of the best experts on this subject based on the ideXlab platform.
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Characterization and correlation of microstructure and Hardness of Ti–6Al–4V sheet surface-treated by pulsed laser
Journal of Alloys and Compounds, 2020Co-Authors: Jiahong Dai, Linjiang Chai, Tingting Wang, Ling Zhang, Ning GuoAbstract:Abstract A hot-rolled Ti–6Al–4V (Ti-64) sheet was surface-treated by pulsed laser at two different powers (100 and 200 W), with microstructural features and Hardness before and after the laser surface treatment (LST) systematically investigated. Results show that after the LST at both powers there are two modification zones with distinct microstructural characteristics: melted zone (MZ) near the laser beam center, completely composed of fine martensitic plates with dense {10–11} nanotwins inside them; heat-affected zone (HAZ) far away from the laser beam center, comprised of mixed structures of short-rod β particles, martensitic plates and untransformed bulk α grains. Hardness measurements reveal that the Hardness of the Ti-64 sheet can be markedly Increased (especially in the MZ) after the LST. In-depth analyses suggest that the Hardness Increase in the MZ can be ascribed to combined contributions from grain refinement, presence of nanotwins and solid solution of alloying elements, while only the structural refinement by fine plate structures contributes to hardening in the HAZ. Comparisons between both the LSTed specimens reveal that increasing the laser power from 100 W to 200 W can effectively enlarge the laser-modified zones (both the MZ and the HAZ) and simultaneously refine plate structures, leading to further Hardness Increase.
Giuseppe Riontino - One of the best experts on this subject based on the ideXlab platform.
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a dsc study of precipitation hardening in a we43 mg alloy
Journal of Thermal Analysis and Calorimetry, 2008Co-Authors: D. Lussana, M. Massazza, Giuseppe RiontinoAbstract:The phase transformations leading to hardening a Mg-Y-Nd-Zr (WE43) alloy submitted to thermal treatments are followed by calorimetric and microHardness measurements. A double-stage thermal treatment is adopted, the first at 210°C for 8 h and the second at 150°C, on samples quenched from a temperature higher than the conventional one. A secondary precipitation of the metastable phase β″ in the second stage makes the Hardness Increase with respect to the primary precipitation.
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A novel thermal treatment on a Mg-4.2Y-2.3Nd-0.6Zr (WE43) alloy
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2008Co-Authors: Giuseppe Riontino, M. Massazza, D. Lussana, Paolo Mengucci, Gianni Barucca, Rafael FerragutAbstract:Abstract A double-stage thermal treatment has been adopted on a Mg–Y–Nd–Zr (WE43) alloy, following suggestions of a previous calorimetric investigation. A secondary precipitation is claimed to occur at a temperature as low as 150 °C after a preliminary precipitation at 210 °C, with the effect of enhancing the Hardness Increase and reducing the annealing times.
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DSC Investigation of Natural Ageing in High-Copper AlCuMg Alloys
Materials Science Forum, 2000Co-Authors: Giuseppe Riontino, H.p. Martinz, Paolo MengucciAbstract:The early stages of precipitation after solution treatment and quenching have been studied in two age-hardenable high-purity AlCuMg alloys having a Cu content of 4.5 wt% and Cu/Mg ratio of 2.6 and 8, by DSC, TEM and Hardness measurements. The investigation has been performed by carrying out DSC scans immediately after quenching and at increasing times at room temperature up to the first sudden Hardness Increase. The analysis of the DSC traces clearly indicates for both compositions that the progressive disappearance of an exothermal precipitation peak at about 80°C in the as-quenched samples is associated with the Hardness Increase observed at room temperature. TEM observations performed after ageing at room temperature for 48 h indicate that the thermal effect associated with the initial Hardness Increase is due to the zones formation. It is therefore concluded that in the investigated alloys the classic mechanism so far accepted involving an interaction between zones and dislocations should be still accepted in order to justify the Hardness Increase in the early stages of precipitation, although the presence of atoms clusters cannot be excluded.
