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Ying Wang - One of the best experts on this subject based on the ideXlab platform.
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Research on Fabrication and Semisolid Processing of Semisolid Slurries of 7075 Aluminum Matrix Composites Reinforced with Nano-Sized SiC Particles
Solid State Phenomena, 2016Co-Authors: Jufu Jiang, Ying Wang, Shou-jing LuoAbstract:Semisolid slurries of 7075 aluminum matrix composite reinforced with nano-sized SiC particles were fabricated by ultrasonic assisted Semisolid stirring (UASS) method. Rheoforming and thixoforming of typical cylindrical parts were investigated. The results show that high-quality Semisolid slurries with spheroidal solid grain of 38 µm were fabricated by UASS. The nano-sized SiC particles were dispersed uniformly due to transient cavitation and acoustic streaming of ultrasonic wave and high and controllable viscosity of Semisolid slurry. Typical cylindrical composite parts with good surface quality and complete filling were rheoformed and thixoformed successfully. Ultimate tensile strength (UTS) of the rheoformed and thixoformed composite parts are enhanced due to addition of nano-sized SiC particles. However, elongation decreased as compared to those of the matrix parts. Maximum UTS of 550 MPa was achieved in the thixoformed composite part with T6 treatment. Increase of dislocation density around the reinforcement particles leads to improvement of the strength and wear resistance of the composite.
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microstructure and mechanical properties of the Semisolid slurries and rheoformed component of nano sized sic 7075 aluminum matrix composite prepared by ultrasonic assisted Semisolid stirring
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2015Co-Authors: Jufu Jiang, Ying WangAbstract:Abstract An innovative method so-called ultrasonic-assisted Semisolid stirring was proposed to fabricate Semisolid slurries of the nano-sized SiC/7075 aluminum matrix composite. In this method, ultrasonic treatment and Semisolid stirring were combined together to disperse the nano-sized SiC and break the primary dendrites of the matrix. The microstructure and mechanical properties of the Semisolid slurries and rheoformed cylinder component were investigated. The results show that ultrasonic treatment dispersed the nano-sized SiC particles well due to the effect of transient cavitation and acoustic streaming. With increase of the stirring time the amount of the spheroidal grains of Semisolid slurries increases, indicating achieving a better Semisolid slurry. When stirring temperature is 620 °C, the 20 min stirring time led to a desirable Semisolid microstructure consisting of a large number of spheroidal grains surrounded by liquid phase. High-quality Semisolid slurries were only achieved at the stirring temperatures of 615 °C and 620 °C upon the 20 min stirring time. Liquid fraction in the regions near to lateral surface is larger than those in the top, bottom and central regions due to main dependence on liquid flow and flow of liquid incorporating solid grains. Yield strength and ultimate tensile strength of rheoformed cylinder components of the nano-sized SiC/7075 aluminum matrix composite increased as compared with those of the 7075 matrix. Yield strength, ultimate tensile strength and elongation of the rheoformed cylinder components of the nano-sized SiC/7075 aluminum matrix composite without T6 are 264 MPa, 357 MPa and elongation of 7.5%, respectively. T6 heat treatment led to a significant improvement of yield strength, ultimate tensile strength and elongation. The mechanical properties of the rheoformed cylinder components with T6 of the nano-sized SiC/7075 aluminum matrix composite involve yield strength of 381 MPa, ultimate tensile strength of 478 MPa and elongation of 8.5%.
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Microstructure and mechanical properties of the Semisolid slurries and rheoformed component of nano-sized SiC/7075 aluminum matrix composite prepared by ultrasonic-assisted Semisolid stirring
Materials Science and Engineering A, 2015Co-Authors: Jufu Jiang, Ying WangAbstract:An innovative method so-called ultrasonic-assisted Semisolid stirring was proposed to fabricate Semisolid slurries of the nano-sized SiC/7075 aluminum matrix composite. In this method, ultrasonic treatment and Semisolid stirring were combined together to disperse the nano-sized SiC and break the primary dendrites of the matrix. The microstructure and mechanical properties of the Semisolid slurries and rheoformed cylinder component were investigated. The results show that ultrasonic treatment dispersed the nano-sized SiC particles well due to the effect of transient cavitation and acoustic streaming. With increase of the stirring time the amount of the spheroidal grains of Semisolid slurries increases, indicating achieving a better Semisolid slurry. When stirring temperature is 620. °C, the 20. min stirring time led to a desirable Semisolid microstructure consisting of a large number of spheroidal grains surrounded by liquid phase. High-quality Semisolid slurries were only achieved at the stirring temperatures of 615. °C and 620. °C upon the 20. min stirring time. Liquid fraction in the regions near to lateral surface is larger than those in the top, bottom and central regions due to main dependence on liquid flow and flow of liquid incorporating solid grains. Yield strength and ultimate tensile strength of rheoformed cylinder components of the nano-sized SiC/7075 aluminum matrix composite increased as compared with those of the 7075 matrix. Yield strength, ultimate tensile strength and elongation of the rheoformed cylinder components of the nano-sized SiC/7075 aluminum matrix composite without T6 are 264. MPa, 357. MPa and elongation of 7.5%, respectively. T6 heat treatment led to a significant improvement of yield strength, ultimate tensile strength and elongation. The mechanical properties of the rheoformed cylinder components with T6 of the nano-sized SiC/7075 aluminum matrix composite involve yield strength of 381. MPa, ultimate tensile strength of 478. MPa and elongation of 8.5%.
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Preparation and thixoforging of Semisolid billet of AZ80 magnesium alloy
Transactions of Nonferrous Metals Society of China, 2010Co-Authors: Jufu Jiang, Ying Wang, Shou-jing LuoAbstract:Semisolid billet of AZ80 magnesium alloy was prepared by new strain induced melt activated (new SIMA) process and thixoforging experiment was performed. The results show that after as-cast AZ80 magnesium alloy is processed by equal channel angular extrusion, microstructure is refined well due to heavy dynamic recrystallization occurring in severe plastic deformation. Compared with Semisolid isothermal treatment and conventional SIMA, Semisolid billet with fine and spheroidal grains are achieved in new SIMA. Thixoforging process of Semisolid billet prepared by new SIMA has many advantages such as good surface quality of final component, high ability to fill cavity and net-shape. The fine and spheroidal grains and high mechanical properties such as tensile strength of 298 MPa and elongation of 28% can be developed in final part thixoforged.
Jufu Jiang - One of the best experts on this subject based on the ideXlab platform.
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Research on Fabrication and Semisolid Processing of Semisolid Slurries of 7075 Aluminum Matrix Composites Reinforced with Nano-Sized SiC Particles
Solid State Phenomena, 2016Co-Authors: Jufu Jiang, Ying Wang, Shou-jing LuoAbstract:Semisolid slurries of 7075 aluminum matrix composite reinforced with nano-sized SiC particles were fabricated by ultrasonic assisted Semisolid stirring (UASS) method. Rheoforming and thixoforming of typical cylindrical parts were investigated. The results show that high-quality Semisolid slurries with spheroidal solid grain of 38 µm were fabricated by UASS. The nano-sized SiC particles were dispersed uniformly due to transient cavitation and acoustic streaming of ultrasonic wave and high and controllable viscosity of Semisolid slurry. Typical cylindrical composite parts with good surface quality and complete filling were rheoformed and thixoformed successfully. Ultimate tensile strength (UTS) of the rheoformed and thixoformed composite parts are enhanced due to addition of nano-sized SiC particles. However, elongation decreased as compared to those of the matrix parts. Maximum UTS of 550 MPa was achieved in the thixoformed composite part with T6 treatment. Increase of dislocation density around the reinforcement particles leads to improvement of the strength and wear resistance of the composite.
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microstructure and mechanical properties of the Semisolid slurries and rheoformed component of nano sized sic 7075 aluminum matrix composite prepared by ultrasonic assisted Semisolid stirring
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2015Co-Authors: Jufu Jiang, Ying WangAbstract:Abstract An innovative method so-called ultrasonic-assisted Semisolid stirring was proposed to fabricate Semisolid slurries of the nano-sized SiC/7075 aluminum matrix composite. In this method, ultrasonic treatment and Semisolid stirring were combined together to disperse the nano-sized SiC and break the primary dendrites of the matrix. The microstructure and mechanical properties of the Semisolid slurries and rheoformed cylinder component were investigated. The results show that ultrasonic treatment dispersed the nano-sized SiC particles well due to the effect of transient cavitation and acoustic streaming. With increase of the stirring time the amount of the spheroidal grains of Semisolid slurries increases, indicating achieving a better Semisolid slurry. When stirring temperature is 620 °C, the 20 min stirring time led to a desirable Semisolid microstructure consisting of a large number of spheroidal grains surrounded by liquid phase. High-quality Semisolid slurries were only achieved at the stirring temperatures of 615 °C and 620 °C upon the 20 min stirring time. Liquid fraction in the regions near to lateral surface is larger than those in the top, bottom and central regions due to main dependence on liquid flow and flow of liquid incorporating solid grains. Yield strength and ultimate tensile strength of rheoformed cylinder components of the nano-sized SiC/7075 aluminum matrix composite increased as compared with those of the 7075 matrix. Yield strength, ultimate tensile strength and elongation of the rheoformed cylinder components of the nano-sized SiC/7075 aluminum matrix composite without T6 are 264 MPa, 357 MPa and elongation of 7.5%, respectively. T6 heat treatment led to a significant improvement of yield strength, ultimate tensile strength and elongation. The mechanical properties of the rheoformed cylinder components with T6 of the nano-sized SiC/7075 aluminum matrix composite involve yield strength of 381 MPa, ultimate tensile strength of 478 MPa and elongation of 8.5%.
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Microstructure and mechanical properties of the Semisolid slurries and rheoformed component of nano-sized SiC/7075 aluminum matrix composite prepared by ultrasonic-assisted Semisolid stirring
Materials Science and Engineering A, 2015Co-Authors: Jufu Jiang, Ying WangAbstract:An innovative method so-called ultrasonic-assisted Semisolid stirring was proposed to fabricate Semisolid slurries of the nano-sized SiC/7075 aluminum matrix composite. In this method, ultrasonic treatment and Semisolid stirring were combined together to disperse the nano-sized SiC and break the primary dendrites of the matrix. The microstructure and mechanical properties of the Semisolid slurries and rheoformed cylinder component were investigated. The results show that ultrasonic treatment dispersed the nano-sized SiC particles well due to the effect of transient cavitation and acoustic streaming. With increase of the stirring time the amount of the spheroidal grains of Semisolid slurries increases, indicating achieving a better Semisolid slurry. When stirring temperature is 620. °C, the 20. min stirring time led to a desirable Semisolid microstructure consisting of a large number of spheroidal grains surrounded by liquid phase. High-quality Semisolid slurries were only achieved at the stirring temperatures of 615. °C and 620. °C upon the 20. min stirring time. Liquid fraction in the regions near to lateral surface is larger than those in the top, bottom and central regions due to main dependence on liquid flow and flow of liquid incorporating solid grains. Yield strength and ultimate tensile strength of rheoformed cylinder components of the nano-sized SiC/7075 aluminum matrix composite increased as compared with those of the 7075 matrix. Yield strength, ultimate tensile strength and elongation of the rheoformed cylinder components of the nano-sized SiC/7075 aluminum matrix composite without T6 are 264. MPa, 357. MPa and elongation of 7.5%, respectively. T6 heat treatment led to a significant improvement of yield strength, ultimate tensile strength and elongation. The mechanical properties of the rheoformed cylinder components with T6 of the nano-sized SiC/7075 aluminum matrix composite involve yield strength of 381. MPa, ultimate tensile strength of 478. MPa and elongation of 8.5%.
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Preparation and thixoforging of Semisolid billet of AZ80 magnesium alloy
Transactions of Nonferrous Metals Society of China, 2010Co-Authors: Jufu Jiang, Ying Wang, Shou-jing LuoAbstract:Semisolid billet of AZ80 magnesium alloy was prepared by new strain induced melt activated (new SIMA) process and thixoforging experiment was performed. The results show that after as-cast AZ80 magnesium alloy is processed by equal channel angular extrusion, microstructure is refined well due to heavy dynamic recrystallization occurring in severe plastic deformation. Compared with Semisolid isothermal treatment and conventional SIMA, Semisolid billet with fine and spheroidal grains are achieved in new SIMA. Thixoforging process of Semisolid billet prepared by new SIMA has many advantages such as good surface quality of final component, high ability to fill cavity and net-shape. The fine and spheroidal grains and high mechanical properties such as tensile strength of 298 MPa and elongation of 28% can be developed in final part thixoforged.
Rubens Caram - One of the best experts on this subject based on the ideXlab platform.
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Thixoforming of titanium: The microstructure and processability of Semisolid Ti-Cu-Fe alloys
Vacuum, 2020Co-Authors: Caio Chaussê De Freitas, Kaio Niitsu Campo, Rubens CaramAbstract:Abstract Thixoforming has been a cost-effective alternative to conventional manufacturing routes because of the advantages in dealing with Semisolid alloys. In this study, the effect of the addition of Fe on the microstructure of three Ti-Cu alloys treated in the Semisolid state was evaluated, and gear-like components were thixoformed to assess the conformability of the alloys. Microstructural characterization indicated that globules in the Semisolid samples exhibited suitable characteristics for thixoforming purposes, whereas the added Fe helped retain the β phase at room temperature. The maximum force required to deform the samples during thixoforming was substantially low (approximately 20 N). The Semisolid alloys completely filled the die, resulting in perfectly formed parts with considerably homogeneous and defect-free structure. Therefore, it was concluded that Ti-Cu-Fe alloys can be promising raw materials for Semisolid processing.
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rapid quenching of Semisolid ti cu alloys insights into globular microstructure formation and coarsening
Acta Materialia, 2017Co-Authors: Kaio Niitsu Campo, Catherine J Parrish, E S N Lopes, Rubens CaramAbstract:Abstract Thixoforming is a typical Semisolid processing route for the production of affordable near-net shape metallic components. In this study, Ti-Cu alloys specifically designed for thixoforming were evaluated to determine their microstructural evolution in the Semisolid state. Ti-(25, 27, 29)Cu (wt.%) alloys were prepared by voltaic arc melting, homogenized, and then hot worked prior to isothermal heat treatment at 1035 °C. Rapid quenching allowed for the investigation of “frozen” Semisolid microstructures. The results indicated the formation of fine grained globular microstructures in all the alloys under study. This was attributed to the deformation process, which was able to break up the dendrites resulting from solidification. The liquid fraction increased with Cu content and its values were consistent with those predicted under equilibrium, although evidence of some nonequilibrium liquid was still present during the time period of analysis. Lastly, coarsening rate constants ( K ) exhibited low values, indicating stable Semisolid microstructures.
T. Haga - One of the best experts on this subject based on the ideXlab platform.
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Effects of casting factors of cooling slope on Semisolid condition
Transactions of Nonferrous Metals Society of China, 2010Co-Authors: T. Haga, Ryoji Nakamura, R. Tago, H. WatariAbstract:The effects of the casting factors such as nozzle size to pour the melt, nozzle height, tilt of the slope and slope length, of the cooling slope on the process to make Semisolid slurry were investigated. The results show that these factors affect the behaviors of the Semisolid slurry on the cooling slope. The tilt of the slope is the factor that has major influence on the behavior of the Semisolid slurry. The cooling roll is developed from the result of the research of the cooling slope. The rotating cooling roll can improve the sticking of the Semisolid slurry on the substrate and it is suitable for making the Semisolid slurry.
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Thixoforming of laminate made from Semisolid cast strips
Journal of Materials Processing Technology, 2004Co-Authors: T. Haga, Plato KapranosAbstract:Abstract In order to reduce the cost of the feedstock, a laminate, in the form of a slug, made from roll cast strips has been used as feedstock for thixoforming. The size of the laminate cube was 40 mm × 40 mm × 40 mm. A high-speed twin roll caster was used to cast A356 strip from which the laminate was manufactured. The strip thickness varied from 3 mm to 2 mm, when the strip was cast at the speed from 30 m/min to 90 m/min. The strip was cast from Semisolid slurry that was produced using a cooling slope. The solid fraction of Semisolid slurry was lower than 10%. The primary crystal of the strip become spheroidal when heated up to Semisolid condition. The ability of the laminate to flow, in the Semisolid condition, was similar to that of conventional feedstock for thixoforming. The mechanical properties of the thixoformed strip laminate were: tensile strength of 315, 253 MPa, 0.2% proof stress and 8% elongation.
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Semisolid strip casting using a twin roll caster equipped with a cooling slope
Journal of Materials Processing Technology, 2002Co-Authors: T. HagaAbstract:Abstract A356 aluminum alloy was subjected to Semisolid strip casting, a type of rheocasting, by use of a melt drag twin roll caster (MDTRC) equipped with a cooling slope. Equipment and operation are very simple; copper rolls were employed, and, in order to increase cooling rate, no lubricant was used. The produced strip did not stick to the roll. Molten metal became Semisolid after flowing down the cooling slope, assuming a solid content of 5–10%. The strip was successfully cast from Semisolid slurry at speeds ranging from 30 to 90 m/min; i.e., casting speed was improved by the effect of Semisolid casting. Strip thickness was 2–2.5 mm. After rolling and heat treatment, tensile strength was 270 MPa and elongation was 18%. After annealing, the strip was not broken when subjected to a 180° bending test. The mechanical properties of the strip were enhanced by Semisolid strip casting. In the middle thickness of the strip, primary crystals were spherical rather than dendritic, and had a size smaller than 50 μm. Eutectic Si was smaller than 5 μm.
Vasudeva Guddattu - One of the best experts on this subject based on the ideXlab platform.
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Comparison of Pharyngoesophageal Segment Biomechanics Between Persons with Total Laryngectomy With and Without Dysphagia Using sEMG: A Multicentric Swallow Study
Dysphagia, 2020Co-Authors: G. Harsha Raj, Venkataraja U. Aithal, Vasudeva GuddattuAbstract:Total laryngectomy (TL) is the surgical treatment option for advanced stage of laryngeal cancer, involving the removal of larynx along with several muscles attached to it. Several anatomical changes occur following the surgery which will in turn affect the swallowing mechanism. The severing of the cricopharyngeus muscle, which is an important muscle of the pharyngoesophageal segment (PES), may lead to dysphagia. Several other causes have also been explained in the literature. Several invasive instruments have been used to identify dysphagia in this population. The present study aimed to identify the differences in the biomechanics of the PES during dry and wet swallow tasks in persons with TL with and without dysphagia. Amplitude and duration of movement of PES was analysed using a non-invasive instrumental method surface electromyography. The results indicate that amplitude of PES movement was significantly higher in dysphagic group for solids and Semisolids. A significantly longer duration was observed for solid consistency for dysphagic group when compared to non-dysphagic group. sEMG evidences suggestive of differences in amplitude and duration between the TL with and without dysphagia groups. Findings also revealed that TL with dysphagia group require more effort to swallow solids and Semisolid consistencies when compared to the effort exerted by them during liquid and dry swallow.
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Comparison of Pharyngoesophageal Segment Biomechanics Between Persons with Total Laryngectomy With and Without Dysphagia Using sEMG: A Multicentric Swallow Study
Dysphagia, 2020Co-Authors: G. Harsha Raj, Venkataraja U. Aithal, Vasudeva GuddattuAbstract:Total laryngectomy (TL) is the surgical treatment option for advanced stage of laryngeal cancer, involving the removal of larynx along with several muscles attached to it. Several anatomical changes occur following the surgery which will in turn affect the swallowing mechanism. The severing of the cricopharyngeus muscle, which is an important muscle of the pharyngoesophageal segment (PES), may lead to dysphagia. Several other causes have also been explained in the literature. Several invasive instruments have been used to identify dysphagia in this population. The present study aimed to identify the differences in the biomechanics of the PES during dry and wet swallow tasks in persons with TL with and without dysphagia. Amplitude and duration of movement of PES was analysed using a non-invasive instrumental method surface electromyography. The results indicate that amplitude of PES movement was significantly higher in dysphagic group for solids and Semisolids. A significantly longer duration was observed for solid consistency for dysphagic group when compared to non-dysphagic group. sEMG evidences suggestive of differences in amplitude and duration between the TL with and without dysphagia groups. Findings also revealed that TL with dysphagia group require more effort to swallow solids and Semisolid consistencies when compared to the effort exerted by them during liquid and dry swallow.
