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Shihching Wu - One of the best experts on this subject based on the ideXlab platform.
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structure and Grindability of dental ti cr alloys
Journal of Alloys and Compounds, 2009Co-Authors: Shihching Wu, Tsungyu Chiang, Wenfu HoAbstract:Abstract The purpose of this study was to investigate the structure and microhardness of a series of binary Ti–Cr alloys with Cr contents up to 30 wt%. In addition, the Grindability was also evaluated using an electric dental handpiece with SiC wheels, with the goal of developing a titanium alloy with better mechanical properties and machinability than commercially pure titanium (c.p. Ti), a metal generally considered to be difficult to machine. This study evaluated the phase and structure of Ti–Cr alloys, using an X-ray diffraction (XRD) for phase analysis and optical microscope for microstructure of the etched alloys. Grindability was evaluated by measuring the amount of metal volume removed after grinding for 1 min. Results indicated that the structure of Ti–Cr alloys is sensitive to the Cr content. The cast c.p. Ti has a hexagonal α phase. With 5 wt% Cr, metastable β phase starts to be retained. With Cr contents higher than 10 wt%, the equi-axed β phase is almost entirely retained. In addition, athermal ω phase was found in the Ti–5Cr and Ti–10Cr alloys. The largest quantity of ω phase and highest microhardness were found in Ti–10Cr alloy. The grinding rate of the Ti–Cr alloys showed a similar tendency to the microhardness. The Ti–10Cr alloy exhibited the best Grindability, especially at 1000 m/min, which presumably due to the brittle nature of the alloy containing the ω phase in the β matrix.
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structure mechanical properties and Grindability of dental ti 10zr x alloys
Materials Science and Engineering: C, 2009Co-Authors: Wenfu Ho, Chunghsiao Cheng, Shihching WuAbstract:Abstract This study aimed to investigate the structure, mechanical properties and Grindability of a binary Ti–Zr alloy added to a series of alloying elements (Nb, Mo, Cr and Fe). The phase and structure of Ti–10Zr–X alloys were evaluated using an X-ray diffraction (XRD) for phase analysis and optical microscope for microstructure of the etched alloys. Three-point bending tests were performed using a desk-top mechanical tester. Grindability was evaluated by measuring the amount of metal volume removed after grinding for 1 min at each of the four rotational speeds of the wheel (500, 750, 1000 or 1200 m/min). Results were compared with c.p. Ti, which was chosen as a control. Results indicated that the phase/crystal structure, microstructure, mechanical properties and Grindability of the Ti–10Zr alloy can be significantly changed by adding small amounts of alloying elements. The alloying elements Nb, Mo, Cr and Fe contributed significantly to increasing the grinding ratio under all grinding conditions, although the grinding rate of all the metals was found to be largely dependent on grinding speed. The Ti–10Zr–1Mo alloy showed increases in microhardness (63%), bending strength (40%), bending modulus (30%) and elastic recovery angle (180%) over those of c.p. Ti, and was also found to have better Grindability. The Ti–10Zr–1Mo alloy could therefore be used for prosthetic dental applications if other conditions necessary for dental casting are met.
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Structure, mechanical properties, and Grindability of dental Ti–Zr alloys
Journal of Materials Science: Materials in Medicine, 2008Co-Authors: Wenfu Ho, Wei-kai Chen, Shihching WuAbstract:Structure, mechanical properties and Grindability of a series of binary Ti–Zr alloys with zirconium contents ranging from 10 to 40 wt% have been investigated. Commercially pure titanium (c.p. Ti) was used as a control. Experimental results indicated that the diffraction peaks of all the Ti–Zr alloys matched those for α Ti. No β-phase peaks were found. The hardness of the Ti–Zr alloys increased as the Zr contents increased, and ranged from 266 HV (Ti–10Zr) to 350 HV (Ti–40Zr). As the concentration of zirconium in the alloys increased, the strength, elastic recovery angles and hardness increased. Moreover, the elastically recoverable angle of Ti–40Zr was higher than of c.p. Ti by as much as 550%. The Grindability of each metal was found to be largely dependent on the grinding conditions. The Ti–40Zr alloy had a higher grinding rate and grinding ratio than c.p. Ti at low speed. The grinding rate of the Ti–40Zr alloy at 500 m/min was about 1.8 times larger than that of c.p. Ti, and the grinding ratio was about 1.6 times larger than that of c.p. Ti. Our research suggested that the Ti–40Zr alloy has better mechanical properties, excellent elastic recovery capability and improved Grindability at low grinding speed. The Ti–40Zr alloy has a great potential for use as a dental machining alloy.
Wenfu Ho - One of the best experts on this subject based on the ideXlab platform.
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structure and Grindability of dental ti cr alloys
Journal of Alloys and Compounds, 2009Co-Authors: Shihching Wu, Tsungyu Chiang, Wenfu HoAbstract:Abstract The purpose of this study was to investigate the structure and microhardness of a series of binary Ti–Cr alloys with Cr contents up to 30 wt%. In addition, the Grindability was also evaluated using an electric dental handpiece with SiC wheels, with the goal of developing a titanium alloy with better mechanical properties and machinability than commercially pure titanium (c.p. Ti), a metal generally considered to be difficult to machine. This study evaluated the phase and structure of Ti–Cr alloys, using an X-ray diffraction (XRD) for phase analysis and optical microscope for microstructure of the etched alloys. Grindability was evaluated by measuring the amount of metal volume removed after grinding for 1 min. Results indicated that the structure of Ti–Cr alloys is sensitive to the Cr content. The cast c.p. Ti has a hexagonal α phase. With 5 wt% Cr, metastable β phase starts to be retained. With Cr contents higher than 10 wt%, the equi-axed β phase is almost entirely retained. In addition, athermal ω phase was found in the Ti–5Cr and Ti–10Cr alloys. The largest quantity of ω phase and highest microhardness were found in Ti–10Cr alloy. The grinding rate of the Ti–Cr alloys showed a similar tendency to the microhardness. The Ti–10Cr alloy exhibited the best Grindability, especially at 1000 m/min, which presumably due to the brittle nature of the alloy containing the ω phase in the β matrix.
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structure mechanical properties and Grindability of dental ti 10zr x alloys
Materials Science and Engineering: C, 2009Co-Authors: Wenfu Ho, Chunghsiao Cheng, Shihching WuAbstract:Abstract This study aimed to investigate the structure, mechanical properties and Grindability of a binary Ti–Zr alloy added to a series of alloying elements (Nb, Mo, Cr and Fe). The phase and structure of Ti–10Zr–X alloys were evaluated using an X-ray diffraction (XRD) for phase analysis and optical microscope for microstructure of the etched alloys. Three-point bending tests were performed using a desk-top mechanical tester. Grindability was evaluated by measuring the amount of metal volume removed after grinding for 1 min at each of the four rotational speeds of the wheel (500, 750, 1000 or 1200 m/min). Results were compared with c.p. Ti, which was chosen as a control. Results indicated that the phase/crystal structure, microstructure, mechanical properties and Grindability of the Ti–10Zr alloy can be significantly changed by adding small amounts of alloying elements. The alloying elements Nb, Mo, Cr and Fe contributed significantly to increasing the grinding ratio under all grinding conditions, although the grinding rate of all the metals was found to be largely dependent on grinding speed. The Ti–10Zr–1Mo alloy showed increases in microhardness (63%), bending strength (40%), bending modulus (30%) and elastic recovery angle (180%) over those of c.p. Ti, and was also found to have better Grindability. The Ti–10Zr–1Mo alloy could therefore be used for prosthetic dental applications if other conditions necessary for dental casting are met.
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Structure, mechanical properties, and Grindability of dental Ti–Zr alloys
Journal of Materials Science: Materials in Medicine, 2008Co-Authors: Wenfu Ho, Wei-kai Chen, Shihching WuAbstract:Structure, mechanical properties and Grindability of a series of binary Ti–Zr alloys with zirconium contents ranging from 10 to 40 wt% have been investigated. Commercially pure titanium (c.p. Ti) was used as a control. Experimental results indicated that the diffraction peaks of all the Ti–Zr alloys matched those for α Ti. No β-phase peaks were found. The hardness of the Ti–Zr alloys increased as the Zr contents increased, and ranged from 266 HV (Ti–10Zr) to 350 HV (Ti–40Zr). As the concentration of zirconium in the alloys increased, the strength, elastic recovery angles and hardness increased. Moreover, the elastically recoverable angle of Ti–40Zr was higher than of c.p. Ti by as much as 550%. The Grindability of each metal was found to be largely dependent on the grinding conditions. The Ti–40Zr alloy had a higher grinding rate and grinding ratio than c.p. Ti at low speed. The grinding rate of the Ti–40Zr alloy at 500 m/min was about 1.8 times larger than that of c.p. Ti, and the grinding ratio was about 1.6 times larger than that of c.p. Ti. Our research suggested that the Ti–40Zr alloy has better mechanical properties, excellent elastic recovery capability and improved Grindability at low grinding speed. The Ti–40Zr alloy has a great potential for use as a dental machining alloy.
Osamu Okuno - One of the best experts on this subject based on the ideXlab platform.
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Grindability of Dental Cast Ti-Zr Alloys
2020Co-Authors: Masatoshi Takahashi, Masafumi Kikuchi, Osamu OkunoAbstract:The purpose of this study was to improve the Grindability of titanium by alloying with zirconium. The Grindability of dental cast Ti-Zr alloy
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Evaluation of Ti-Cr-Cu alloys for dental applications
Journal of Materials Engineering and Performance, 2005Co-Authors: Marie Koike, Osamu Okuno, Toru Okabe, Masayuki Itoh, Kohei Kimura, Osamu Takeda, Toru H. OkabeAbstract:This study examined the characteristics of as-cast Ti-Cr(7–19%)-Cu(3–7%) (all percentages in this article are mass%) alloys to evaluate their suitability for dental applications; studies on the alloy structures and mechanical properties, Grindability, and corrosion behavior were included in the investigation. The alloys were centrifugally cast and bench-cooled in investment molds. The x-ray diffractometry of the as-cast alloys bench-cooled in the molds indicated the following phases: α+β+ω in the 7% Cr and 7% Cr+3% Cu; β+ω in the 13%Cr; and β in the 13%Cr+3% Cu through the 19%Cr+3% Cu alloys. The strengths of the binary β Ti-Cr and ternary β Ti-Cr-Cu alloys with 13 and 19% Cr were approximately two times higher than those of CP Ti. The alloy ductility was dependent on the chemical composition and thus, the microstructure. The 7% Cr alloys were extremely brittle and hard due to the ω phase, but the ductility was restored in the 13 and 19% Cr alloys. The hardness (HV) of the cast 13 and 19% Cr alloys was approximately 300–350 compared with a value of 200 for CP Ti. The Grindability of the cast alloys was examined using a rotating SiC wheel at speeds (circumferential) of 500 and 1250 m/min. At the higher speed, the Grindability of the 13 and 19% Cr alloys increased with the Cu content. The Grindability of the 13% Cr alloy with 7% Cu was similar to that of CP Ti. Evaluation of the corrosion behavior in an artificial saliva revealed that the alloys are like many other titanium alloys within the normal intraoral oxidation potential. The wear resistance testing of these alloys also showed favorable results.
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the Grindability and wear of ti cu alloys for dental applications
JOM, 2004Co-Authors: Toru Okabe, Chikahiro Ohkubo, Masafumi Kikuchi, Marie Koike, Osamu OkunoAbstract:To optimize the properties of titanium for use in dentistry, alloying is necessary. This study reports on the characterization of some titanium alloys for Grindability, wear, and corrosion resistance. Improvements in Grindability and wear seemed to occur with the presence of the eutectoid in the alloy.
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mechanical properties and Grindability of dental cast ti nb alloys
Dental Materials Journal, 2003Co-Authors: Masafumi Kikuchi, Masatoshi Takahashi, Osamu OkunoAbstract:Aiming at developing a dental titanium alloy with better mechanical properties and machinability than unalloyed titanium, a series of Ti-Nb alloys with Nb concentrations up to 30% was made. They were cast into magnesia-based molds using a dental casting machine and the mechanical properties and Grindability of the castings were examined. The hardness of the alloys with Nb concentrations of 5% and above was significantly higher than that of titanium. The yield strength and tensile strength of the alloys with Nb concentrations of 10% and above were significantly higher than those of titanium, while the elongation was significantly lower. A small addition of niobium to titanium did not contribute to improving the Grindability of titanium. The Ti-30%Nb alloy exhibited significantly better Grindability at low grinding speed with higher hardness, strength, and Young's modulus than titanium, presumably due to precipitation of the ω phase in the β matrix.
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Grindability of dental cast ti ag and ti cu alloys
Dental Materials Journal, 2003Co-Authors: Masafumi Kikuchi, Masatoshi Takahashi, Toru Okabe, Osamu OkunoAbstract:Experimental Ti-Ag alloys (5, 10, and 20mass% Ag) and Ti-Cu alloys (2, 5, and 10mass% Cu) were cast into magnesia molds using a dental casting machine, and their Grindability was investigated. At the lowest grinding speed (500m⋅min-1), there were no statistical differences among the Grindability values of the titanium and titanium alloys. The Grindability of the alloys increased as the grinding speed increased. At the highest grinding speed (1500m⋅min-1), the Grindability of the 20% Ag, 5% Cu, and 10% Cu alloys was significantly higher than that of titanium. It was found that alloying with silver or copper improved the Grindability of titanium, particularly at a high speed. It appeared that the decrease in elongation caused by the precipitation of small amounts of intermetallic compounds primarily contributed to the favorable Grindability of the experimental alloys.
Toru Okabe - One of the best experts on this subject based on the ideXlab platform.
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evaluation of titanium alloy fabricated using electron beam melting system for dental applications
Journal of Materials Processing Technology, 2011Co-Authors: Mari Koike, Kelly Martinez, Lilly Guo, Gilbe Chahine, Radova Kovacevic, Toru OkabeAbstract:Abstract In recently advanced rapid prototyping and manufacturing methods, one additional process is to use an electron beam to fabricate metal objects by the layer by layer sintering and/or melting metal powder. This method is often called electron beam melting (EBM). This study examined the mechanical properties, the Grindability and corrosion resistance of Ti–6Al–4V ELI (extra low interstitial) specimens which were fabricated by the electron beam melting (EBM) process. Dumbbell-shaped specimens and two kinds of plate specimens were prepared using the Ti–6Al–4V ELI powder in the EBM system. The yield strength, tensile strength, modulus of elasticity and percent elongation at a crosshead speed of 0.25 mm/min were tested. The Vickers hardness in interior structures was determined. Grindability was evaluated as volume loss (mm 3 ) when the specimen was abraded using a SiC wheel at 1250 m/min for 1 min. Lastly, corrosion behavior was examined using the dynamic potentiostatic polarization technique in an artificial saliva at 37 °C. As controls, cast and commercial wrought alloys of Ti–6Al–4V ELI and commercially pure titanium (CP Ti) were evaluated. Cast specimens were prepared in a centrifugal casting machine using a MgO based mold. For the cast specimens, all the mechanical properties, Grindability and corrosion characteristics were tested. On the other hand, for wrought specimens, only Grindability and corrosion properties were tested. The yield and tensile strength of the as-fabricated Ti–6Al–4V ELI specimens without any additional metallurgical treatments were found to be 735 MPa and 775 MPa, respectively. The elongation was 2.3%. These values are well within many of precious and non-precious dental casting alloys.
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Evaluation of Ti-Cr-Cu alloys for dental applications
Journal of Materials Engineering and Performance, 2005Co-Authors: Marie Koike, Osamu Okuno, Toru Okabe, Masayuki Itoh, Kohei Kimura, Osamu Takeda, Toru H. OkabeAbstract:This study examined the characteristics of as-cast Ti-Cr(7–19%)-Cu(3–7%) (all percentages in this article are mass%) alloys to evaluate their suitability for dental applications; studies on the alloy structures and mechanical properties, Grindability, and corrosion behavior were included in the investigation. The alloys were centrifugally cast and bench-cooled in investment molds. The x-ray diffractometry of the as-cast alloys bench-cooled in the molds indicated the following phases: α+β+ω in the 7% Cr and 7% Cr+3% Cu; β+ω in the 13%Cr; and β in the 13%Cr+3% Cu through the 19%Cr+3% Cu alloys. The strengths of the binary β Ti-Cr and ternary β Ti-Cr-Cu alloys with 13 and 19% Cr were approximately two times higher than those of CP Ti. The alloy ductility was dependent on the chemical composition and thus, the microstructure. The 7% Cr alloys were extremely brittle and hard due to the ω phase, but the ductility was restored in the 13 and 19% Cr alloys. The hardness (HV) of the cast 13 and 19% Cr alloys was approximately 300–350 compared with a value of 200 for CP Ti. The Grindability of the cast alloys was examined using a rotating SiC wheel at speeds (circumferential) of 500 and 1250 m/min. At the higher speed, the Grindability of the 13 and 19% Cr alloys increased with the Cu content. The Grindability of the 13% Cr alloy with 7% Cu was similar to that of CP Ti. Evaluation of the corrosion behavior in an artificial saliva revealed that the alloys are like many other titanium alloys within the normal intraoral oxidation potential. The wear resistance testing of these alloys also showed favorable results.
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the Grindability and wear of ti cu alloys for dental applications
JOM, 2004Co-Authors: Toru Okabe, Chikahiro Ohkubo, Masafumi Kikuchi, Marie Koike, Osamu OkunoAbstract:To optimize the properties of titanium for use in dentistry, alloying is necessary. This study reports on the characterization of some titanium alloys for Grindability, wear, and corrosion resistance. Improvements in Grindability and wear seemed to occur with the presence of the eutectoid in the alloy.
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Grindability of dental cast ti ag and ti cu alloys
Dental Materials Journal, 2003Co-Authors: Masafumi Kikuchi, Masatoshi Takahashi, Toru Okabe, Osamu OkunoAbstract:Experimental Ti-Ag alloys (5, 10, and 20mass% Ag) and Ti-Cu alloys (2, 5, and 10mass% Cu) were cast into magnesia molds using a dental casting machine, and their Grindability was investigated. At the lowest grinding speed (500m⋅min-1), there were no statistical differences among the Grindability values of the titanium and titanium alloys. The Grindability of the alloys increased as the grinding speed increased. At the highest grinding speed (1500m⋅min-1), the Grindability of the 20% Ag, 5% Cu, and 10% Cu alloys was significantly higher than that of titanium. It was found that alloying with silver or copper improved the Grindability of titanium, particularly at a high speed. It appeared that the decrease in elongation caused by the precipitation of small amounts of intermetallic compounds primarily contributed to the favorable Grindability of the experimental alloys.
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Grindability of dental cast ti ag and ti cu alloys
Dental Materials Journal, 2003Co-Authors: Masafumi Kikuchi, Masatoshi Takahashi, Toru Okabe, Osamu OkunoAbstract:Experimental Ti-Ag alloys (5, 10, and 20mass% Ag) and Ti-Cu alloys (2, 5, and 10mass% Cu) were cast into magnesia molds using a dental casting machine, and their Grindability was investigated. At the lowest grinding speed (500m⋅min-1), there were no statistical differences among the Grindability values of the titanium and titanium alloys. The Grindability of the alloys increased as the grinding speed increased. At the highest grinding speed (1500m⋅min-1), the Grindability of the 20% Ag, 5% Cu, and 10% Cu alloys was significantly higher than that of titanium. It was found that alloying with silver or copper improved the Grindability of titanium, particularly at a high speed. It appeared that the decrease in elongation caused by the precipitation of small amounts of intermetallic compounds primarily contributed to the favorable Grindability of the experimental alloys.
Amirhossein Bagherieh - One of the best experts on this subject based on the ideXlab platform.
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studies of the relationship between petrography and Grindability for kentucky coals using artificial neural network
International Journal of Coal Geology, 2008Co-Authors: James C Hower, Amirhossein Bagherieh, E. JorjaniAbstract:Abstract Although there are several formulas available for predicting Hardgrove Grindability of coal, most of them are linear and do not simultaneously take into consideration most of the relevant factors. The artificial neural network is an information processing tool that is capable of establishing an input–output relationship by extracting controlling features from a database presented to the network. In this paper, a neural network approach was proposed to deal with the Grindability behavior of coal. 195 sets of experimental data were evaluated with artificial neural network to predict the HGI of Kentucky coals. Two different kinds of the trained artificial neural network were undertaken using the database created in this study. It is shown from the examples that the artificial neural network adequately recognized the characteristics of the coal experimental data sets, retaining a generality for further prediction. It is believed that an artificial neural network based prediction procedure shown in this paper can be further employed for Hardgrove Grindability index prediction. The influence of liptinite, vitrinite, ash, and sulfur content on HGI was studied by a parametric study.
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prediction of coal Grindability based on petrography proximate and ultimate analysis using multiple regression and artificial neural network models
Fuel Processing Technology, 2008Co-Authors: Chehreh S Chelgani, Sh Mesroghli, E. Jorjani, Amirhossein BagheriehAbstract:Abstract The effects of proximate and ultimate analysis, maceral content, and coal rank (Rmax) for a wide range of Kentucky coal samples from calorific value of 4320 to 14960 (BTU/lb) (10.05 to 34.80 MJ/kg) on Hardgrove Grindability Index (HGI) have been investigated by multivariable regression and artificial neural network methods (ANN). The stepwise least square mathematical method shows that the relationship between (a) Moisture, ash, volatile matter, and total sulfur; (b) ln (total sulfur), hydrogen, ash, ln ((oxygen + nitrogen)/carbon) and moisture; (c) ln (exinite), semifusinite, micrinite, macrinite, resinite, and Rmax input sets with HGI in linear condition can achieve the correlation coefficients (R2) of 0.77, 0.75, and 0.81, respectively. The ANN, which adequately recognized the characteristics of the coal samples, can predict HGI with correlation coefficients of 0.89, 0.89 and 0.95 respectively in testing process. It was determined that ln (exinite), semifusinite, micrinite, macrinite, resinite, and Rmax can be used as the best predictor for the estimation of HGI on multivariable regression (R2 = 0.81) and also artificial neural network methods (R2 = 0.95). The ANN based prediction method, as used in this paper, can be further employed as a reliable and accurate method, in the hardgrove Grindability index prediction.
