The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
F J Gotor - One of the best experts on this subject based on the ideXlab platform.
-
liquid phase Sintering of ti c n based cermets the effects of binder nature and content on the solubility and wettability of hard ceramic phases
Journal of Alloys and Compounds, 2013Co-Authors: J M Cordoba, E Chicardi, F J GotorAbstract:Abstract Different commercial TiC–TiN/Co/Ni mixtures were used as raw materials for Ti(C,N) cermets, and the effects of the Sintering parameters (binder content, binder nature, Sintering Time and additives) on the final hard ceramic phase were studied at the Sintering temperature of 1400 °C. When Co is used as the binder medium, it is possible to completely convert the starting commercial TiC–TiN mixture into TiC x N 1− x . When Ni is used, which exhibits lower solubilising capacity than Co, the total conversion can never be reached and the metallurgical reactions between TiC and TiN during the liquid-phase Sintering are more dependent on the Sintering Time than on the binder content. However, the use of Co–Ni mixtures, showing a synergic effect between the wettability capacity of Ni and the solubilising capacity of Co, enhances the metallurgical reactions at short Sintering Times.
-
effect of Sintering Time on the microstructure and mechanical properties of ti ta c n based cermets
International Journal of Refractory Metals & Hard Materials, 2013Co-Authors: E Chicardi, J M Cordoba, Y Torres, M J Sayagues, Jose Rodriguez, F J GotorAbstract:Abstract Complete solid-solution cermets based on titanium–tantalum carbonitride using a starting nominal composition with 80 wt.% of (Ti 0.8 Ta 0.2 )(C 0.5 N 0.5 ) and 20 wt.% of Co were performed by pressure-less Sintering at 1550 °C for different Times (from 0 to 180 min) in an inert atmosphere. Chemical and phase analyses were conducted using X-ray diffraction (XRD), elemental analysis and energy dispersive X-ray spectrometry (EDX). The binder mean free path and the contiguity of the carbonitride particles were used to rationalise the microstructural effects of the mechanical behaviour. Mechanical characterisation included determining the Vickers hardness, the fracture toughness (conventional indentation microfractures, IM ), the dynamic Young's modulus (ultrasonic technique), the biaxial strength (ball on three ball) and a detailed fractographic examination. Finally, the experimental findings were combined with a theoretical fracture mechanics analysis to estimate the critical processing flaw sizes. Binder-less carbonitride clusters, pores and coarse carbonitride grains were the main defects observed and were responsible for the fractures.
-
effect of Sintering Time on the microstructure and mechanical properties of ti ta c n based cermets
International Journal of Refractory Metals & Hard Materials, 2013Co-Authors: E Chicardi, J M Cordoba, Y Torres, M J Sayagues, Jose A Rodriguez, F J GotorAbstract:Abstract Complete solid-solution cermets based on titanium–tantalum carbonitride using a starting nominal composition with 80 wt.% of (Ti 0.8 Ta 0.2 )(C 0.5 N 0.5 ) and 20 wt.% of Co were performed by pressure-less Sintering at 1550 °C for different Times (from 0 to 180 min) in an inert atmosphere. Chemical and phase analyses were conducted using X-ray diffraction (XRD), elemental analysis and energy dispersive X-ray spectrometry (EDX). The binder mean free path and the contiguity of the carbonitride particles were used to rationalise the microstructural effects of the mechanical behaviour. Mechanical characterisation included determining the Vickers hardness, the fracture toughness (conventional indentation microfractures, IM ), the dynamic Young's modulus (ultrasonic technique), the biaxial strength (ball on three ball) and a detailed fractographic examination. Finally, the experimental findings were combined with a theoretical fracture mechanics analysis to estimate the critical processing flaw sizes. Binder-less carbonitride clusters, pores and coarse carbonitride grains were the main defects observed and were responsible for the fractures.
E Chicardi - One of the best experts on this subject based on the ideXlab platform.
-
liquid phase Sintering of ti c n based cermets the effects of binder nature and content on the solubility and wettability of hard ceramic phases
Journal of Alloys and Compounds, 2013Co-Authors: J M Cordoba, E Chicardi, F J GotorAbstract:Abstract Different commercial TiC–TiN/Co/Ni mixtures were used as raw materials for Ti(C,N) cermets, and the effects of the Sintering parameters (binder content, binder nature, Sintering Time and additives) on the final hard ceramic phase were studied at the Sintering temperature of 1400 °C. When Co is used as the binder medium, it is possible to completely convert the starting commercial TiC–TiN mixture into TiC x N 1− x . When Ni is used, which exhibits lower solubilising capacity than Co, the total conversion can never be reached and the metallurgical reactions between TiC and TiN during the liquid-phase Sintering are more dependent on the Sintering Time than on the binder content. However, the use of Co–Ni mixtures, showing a synergic effect between the wettability capacity of Ni and the solubilising capacity of Co, enhances the metallurgical reactions at short Sintering Times.
-
effect of Sintering Time on the microstructure and mechanical properties of ti ta c n based cermets
International Journal of Refractory Metals & Hard Materials, 2013Co-Authors: E Chicardi, J M Cordoba, Y Torres, M J Sayagues, Jose Rodriguez, F J GotorAbstract:Abstract Complete solid-solution cermets based on titanium–tantalum carbonitride using a starting nominal composition with 80 wt.% of (Ti 0.8 Ta 0.2 )(C 0.5 N 0.5 ) and 20 wt.% of Co were performed by pressure-less Sintering at 1550 °C for different Times (from 0 to 180 min) in an inert atmosphere. Chemical and phase analyses were conducted using X-ray diffraction (XRD), elemental analysis and energy dispersive X-ray spectrometry (EDX). The binder mean free path and the contiguity of the carbonitride particles were used to rationalise the microstructural effects of the mechanical behaviour. Mechanical characterisation included determining the Vickers hardness, the fracture toughness (conventional indentation microfractures, IM ), the dynamic Young's modulus (ultrasonic technique), the biaxial strength (ball on three ball) and a detailed fractographic examination. Finally, the experimental findings were combined with a theoretical fracture mechanics analysis to estimate the critical processing flaw sizes. Binder-less carbonitride clusters, pores and coarse carbonitride grains were the main defects observed and were responsible for the fractures.
-
effect of Sintering Time on the microstructure and mechanical properties of ti ta c n based cermets
International Journal of Refractory Metals & Hard Materials, 2013Co-Authors: E Chicardi, J M Cordoba, Y Torres, M J Sayagues, Jose A Rodriguez, F J GotorAbstract:Abstract Complete solid-solution cermets based on titanium–tantalum carbonitride using a starting nominal composition with 80 wt.% of (Ti 0.8 Ta 0.2 )(C 0.5 N 0.5 ) and 20 wt.% of Co were performed by pressure-less Sintering at 1550 °C for different Times (from 0 to 180 min) in an inert atmosphere. Chemical and phase analyses were conducted using X-ray diffraction (XRD), elemental analysis and energy dispersive X-ray spectrometry (EDX). The binder mean free path and the contiguity of the carbonitride particles were used to rationalise the microstructural effects of the mechanical behaviour. Mechanical characterisation included determining the Vickers hardness, the fracture toughness (conventional indentation microfractures, IM ), the dynamic Young's modulus (ultrasonic technique), the biaxial strength (ball on three ball) and a detailed fractographic examination. Finally, the experimental findings were combined with a theoretical fracture mechanics analysis to estimate the critical processing flaw sizes. Binder-less carbonitride clusters, pores and coarse carbonitride grains were the main defects observed and were responsible for the fractures.
J M Cordoba - One of the best experts on this subject based on the ideXlab platform.
-
liquid phase Sintering of ti c n based cermets the effects of binder nature and content on the solubility and wettability of hard ceramic phases
Journal of Alloys and Compounds, 2013Co-Authors: J M Cordoba, E Chicardi, F J GotorAbstract:Abstract Different commercial TiC–TiN/Co/Ni mixtures were used as raw materials for Ti(C,N) cermets, and the effects of the Sintering parameters (binder content, binder nature, Sintering Time and additives) on the final hard ceramic phase were studied at the Sintering temperature of 1400 °C. When Co is used as the binder medium, it is possible to completely convert the starting commercial TiC–TiN mixture into TiC x N 1− x . When Ni is used, which exhibits lower solubilising capacity than Co, the total conversion can never be reached and the metallurgical reactions between TiC and TiN during the liquid-phase Sintering are more dependent on the Sintering Time than on the binder content. However, the use of Co–Ni mixtures, showing a synergic effect between the wettability capacity of Ni and the solubilising capacity of Co, enhances the metallurgical reactions at short Sintering Times.
-
effect of Sintering Time on the microstructure and mechanical properties of ti ta c n based cermets
International Journal of Refractory Metals & Hard Materials, 2013Co-Authors: E Chicardi, J M Cordoba, Y Torres, M J Sayagues, Jose Rodriguez, F J GotorAbstract:Abstract Complete solid-solution cermets based on titanium–tantalum carbonitride using a starting nominal composition with 80 wt.% of (Ti 0.8 Ta 0.2 )(C 0.5 N 0.5 ) and 20 wt.% of Co were performed by pressure-less Sintering at 1550 °C for different Times (from 0 to 180 min) in an inert atmosphere. Chemical and phase analyses were conducted using X-ray diffraction (XRD), elemental analysis and energy dispersive X-ray spectrometry (EDX). The binder mean free path and the contiguity of the carbonitride particles were used to rationalise the microstructural effects of the mechanical behaviour. Mechanical characterisation included determining the Vickers hardness, the fracture toughness (conventional indentation microfractures, IM ), the dynamic Young's modulus (ultrasonic technique), the biaxial strength (ball on three ball) and a detailed fractographic examination. Finally, the experimental findings were combined with a theoretical fracture mechanics analysis to estimate the critical processing flaw sizes. Binder-less carbonitride clusters, pores and coarse carbonitride grains were the main defects observed and were responsible for the fractures.
-
effect of Sintering Time on the microstructure and mechanical properties of ti ta c n based cermets
International Journal of Refractory Metals & Hard Materials, 2013Co-Authors: E Chicardi, J M Cordoba, Y Torres, M J Sayagues, Jose A Rodriguez, F J GotorAbstract:Abstract Complete solid-solution cermets based on titanium–tantalum carbonitride using a starting nominal composition with 80 wt.% of (Ti 0.8 Ta 0.2 )(C 0.5 N 0.5 ) and 20 wt.% of Co were performed by pressure-less Sintering at 1550 °C for different Times (from 0 to 180 min) in an inert atmosphere. Chemical and phase analyses were conducted using X-ray diffraction (XRD), elemental analysis and energy dispersive X-ray spectrometry (EDX). The binder mean free path and the contiguity of the carbonitride particles were used to rationalise the microstructural effects of the mechanical behaviour. Mechanical characterisation included determining the Vickers hardness, the fracture toughness (conventional indentation microfractures, IM ), the dynamic Young's modulus (ultrasonic technique), the biaxial strength (ball on three ball) and a detailed fractographic examination. Finally, the experimental findings were combined with a theoretical fracture mechanics analysis to estimate the critical processing flaw sizes. Binder-less carbonitride clusters, pores and coarse carbonitride grains were the main defects observed and were responsible for the fractures.
M J Hadianfard - One of the best experts on this subject based on the ideXlab platform.
-
the effect of Sintering Time on the densification and mechanical properties of a mechanically alloyed cr mn n stainless steel
Materials & Design, 2010Co-Authors: E Salahinejad, Rasool Amini, Mehdi Marasi, M J HadianfardAbstract:Abstract Sintering is an essential stage in powder metallurgy, which affects the final microstructure and performance of the part. This study is concerned with the Sintering and mechanical behaviors of Fe–18Cr–8Mn–0.9N stainless steel prepared from mechanically alloyed amorphous/nanocrystalline powders. The contribution of Sintering Time to the densification at 1100 °C is considered and a sluggish densification is found for the alloy. Furthermore, the correlation between the microstructure and mechanical properties of the fabricated porous parts is studied. It is found that the yield stress is affected by both porosity and the material’s intrinsic yield strength. Nonetheless, the effect of porosity on the overall hardness typically prevails over the effect of matrix hardness. Interestingly, even after Sintering at 1100 °C for up to 20 h, the nanometric structure of the material is retained.
Byoungchul Shin - One of the best experts on this subject based on the ideXlab platform.
-
effect of Sintering Time on electrical characteristics and dc accelerated aging behaviors of zn pr co cr dy oxide based varistors
Journal of Materials Science: Materials in Electronics, 2005Co-Authors: Choonwoo Nahm, Byoungchul ShinAbstract:The electrical properties and DC accelerated aging behaviors for nonlinear properties and dielectric characteristics of the varistors, which are composed of ZnO–Pr6O11CoO–Cr2O3–Dy2O3 (ZPCCD)-based ceramics, were investigated for different Sintering Times. The increase of Sintering Time deteriorated nonlineacy by decreasing a nonlinear exponent from 66.6 to. 46.5 and increasing a leakage current from 1.2 to 3.5 μA. But, the appropriate Sintering Time decreased a dissipation factor and improved the DC accelerated aging characteristics. The varistors sintered for 2 h exhibited not only relatively high nonlinearity, with the nonlinear exponent of 54.8, the leakage current of 2.5 μA, and dissipation factor of 0.0263 but also the highest stability, in which the variation rates of varistor voltage, nonlinear exponent, leakage current, and dissipation factor are −1.19%, −4.0%, +75.8%, and +43.8%, respectively. As Sintering Time increases, the donor concentration and density of interface states increased in the range of 1.08 × 1018–1.48× 1018/cm3 and 3.40 × 1012–3.86 × 1012/cm2, respectively. However the barrier height increased with increasing Sintering Time.
-
effect of Sintering Time on electrical properties and stability against dc accelerated aging of y2o3 doped zno pr6o11 based varistor ceramics
Ceramics International, 2004Co-Authors: Choonwoo Nahm, Byoungchul ShinAbstract:Abstract The electrical nonlinear properties and their stability against DC accelerated aging stress of varistors composed of Z nO– P r 6 O 11 – C oO– C r 2 O 3 – Y 2 O 3 (ZPCCY)-based ceramics were investigated at various Sintering Times. The increase of Sintering Time deteriorated the nonlinearity, whereas improved the stability. The highest nonlinearity was obtained from the varistor ceramics sintered for 1 h, with 51.2 in nonlinear exponent and 1.3 μA in leakage current. The varistor ceramics sintered for 2 h exhibited not only relatively high nonlinearity, which the nonlinear exponent is 38.6 and the leakage current is 3.9 μA, but also the highest stability, in which the variation rates of varistor voltage, nonlinear exponent, leakage current, and dissipation factor are −0.8%,−1.8%, +74.4%, and +0.9%, respectively, for DC accelerated aging stress such as 0.95 V 1 mA /150 °C/12 h.