Papers by Keyword: Sintering Temperature

Abstract: PM Co-Cr-Mo (F75) alloys are widely used in implants due to their mechanical properties, good wear resistance and as well as biocompatibility. Currently, they are fabricated by casting technique. In this present research, F75 was fabricated by powder metallurgy technique. The powder was mixed with 2 wt. % of stearic acid in order to form green body and compacted at 500 MPa. The effect of sintering temperature was investigated to observe its effect to the microstructure of F75 (Co-Cr-Mo). Samples were sintered for 2 hours at 2 different temperatures (1250°C and 1300°C) with 10°C/min in argon atmosphere. Physical properties such as density and porosity were obtained by Archimedes principle. Microstructure was observed by using optical microscope Olympus BX41M. The results indicate that increasing the sintering temperature will influence the density and porosity, thus the microstructure itself.

Abstract: The composites sample of Zinc Ferrite (Zn_xFe_3-xO₄) were prepared by mixing zinc oxide (ZnO) and iron oxide (Fe₂O₃) via different stoichiometry (ratio) with Zn_xFe_3-xO₄, for x= 0,0.2,0.4,0.6,0.8 and sintering temperature at 1000 °C, 1100 °C,1200 °C for six hours. The phase compositions of the synthesized Zinc Ferrite (ZF) were verified using X-ray Diffraction (XRD), hardness testing using hardness Vickers, density and thermal conductivity for composite was studied. The result shows the sample with ratio 0.8 and 1200 ^oC sintering temperature gives the highest value of thermal conductivity with 9.7614 W/m²K and the lowest thermal resistance with 0.1024 m²K / W.

Abstract: Al/B composite is a new structural-functional integration material, which has a promising potential in future application due to their good combination of neutron shielding property and mechanical property. In order to obtain sintering process parameters of Al/B composite, the mold pressure, sintering temperature and the composition of powders were investigated and the physical properties of Al/B composite also systematically studied. In addition, the surface morphology of Al/B composite was analyzed. The experimental results indicate that the relative density will be higher when the mold pressure was bigger in appropriate pressure intervals, and when the mold pressure was more than 144MPa, the composites was difficult for molding because of the great internal stress. From the analysis of morphology, it shows that the best sinter temperature interval is 550-580°C. From the studies of composition of powders, it has been found that the percentage of Al affect the density and hardness. The density will be higher if the percentage of Al is higher.

Abstract: Glazed hollow bead, a kind of inorganic lightweight aggregate that has been recently developed, has raised high concern in the field of thermal insulation of building wall due to its low thermal conductivity, low water absorption, good fireproof performance and relatively high compression strength. In this paper, the preparation of this thermal insulation glazed hollow bead material was introduced in detail, the influence of the amount of gel material on bulk density, porosity, thermal conductivity, compression strength of the thermal insulation glazed hollow bead material was investigated, the surface morphology and surface components were characterized by means of SEM and EDS. Results showed that the density, thermal conductivity and compression strength increased while the porosity decreased with the amount of gel material increasing. Appropriate temperature enables gel material to work at optimal level under which the compression strength increases, on the other hand, the porosity also increases, therefore, the thermal conductivity decreases.

Abstract: In the present work, the effects of sintering temperature on physical and mechanical properties of HA/YSZ nanocomposites were investigated. The obtained results have been proved that the sintering temperature contributed greatly to densification and the compressive strength with the highest at 4.80 g/cm³ and 74.20 MPa for 80 wt.% of YSZ content in nanocomposites, respectively. The densification increased with increasing sintering temperature, where the compressive strength value was related with densification for the same ratio amount of YSZ. The higher the YSZ contents also significantly produced the ascendant of densification and the compressive strength.

Abstract: Sr - doped NiO ceramic was prepared using solid state method. The calcination temperature used at 950 oC for 4 hours and the sintering temperatures was varied from 1100 to 1300 oC for 3 hours. The results depict the microstructures increasing in grains size (1-8 μm) by increase of sintering temperatures. The density and porosity testing support the result of microstructures analysis. The larger grains size induced the increase in density and lower in porosity. The dielectric properties is observed in a wide frequency range of (1 - 1 000 MHz). The increase of dielectric constant is associated with the decrease of dielectric loss. The optimum sintering temperature was obtained at 1200 oC depict the grain size range (1 - 2 μm) with highest dielectric constant (1.61 x 103) and lowest dielectric loss (1.15) at 1MHz.

Abstract: Cordierite glass of non stoichiometric (2.8MgO 1.5Al₂O₃ 5SiO₂) can be used to synthesis the synthetic gems because of it properties. The colorant glaze material; 2% , which from trace element cam give colorant to cordierite glass sample. The XRD analysis give result that α-cordierite formed at temperature 1250°C. The density and porosity of cordierite glass decreased as the sintering temperature increased. The hardness from Vickers Hardness are increased as the sintering temperature incerased.

Abstract: Cobalt chromium molybdenum (CoCrMo) alloy is widely used in artificial hip and knee joints because of their excellence corrosion and wear resistance, as well as good mechanical properties and biocompatibility. This study investigates the effect of sintering temperature on the microstructure and mechanical properties of CoCrMo using powder metallurgy technique. CoCrMo powder was mixed with zinc stearate and then put into the shaker mixer at 65 rpm for 3 hours. The powder was then compacted at a pressure of 18T using an automated hydraulic press and sintered at a temperature in the range of 1200 – 1400 °C under 95 Vol% N₂/ 5 Vol% H₂ atmosphere. The microstructure, physical and mechanical properties of the samples are analyzed using scanning electron microscopy (SEM), Vickers’s microhardness tester and transverse rupture strength (TRS). The study reveals that the density, hardness and strength of CoCrMo samples increase as sintering temperature increases.

Abstract: The demand for tetragonal zirconia as a dental restorative material has been increasing because of its excellent mechanical properties and resemblance to natural tooth color, as well as its excellent biological compatibility. Cerium oxide (CeO₂) has been added to yttria-stabilized zirconia (Y-TZP), and studies have demonstrated that the stability of the tetragonal phase can be significantly improved. Y-TZP with 5wt% CeO₂ as a second stabilizer was developed via colloidal process, followed by a suitable sintering process. According to the literature, the sintering process is the most crucial stage in ceramic processing to obtain the most homogeneous structure with high density and hardness. This study aims to investigate the effect of sintering temperature on the mechanical properties of nanostructured ceria–zirconia fabricated via colloidal processing and slip casting process with cold isostatic pressing (CIP). Twenty-five pellet specimens were prepared from ceria–zirconia with 20 nm particle size. CeO₂ nanopowder was mixed with Y-TZP nanopowder via colloidal processing. The consolidation of the powder was done via slip casting followed by CIP. The samples were divided into five different sintering temperatures with. Results from FESEM, density and hardness analyses demonstrated statistically significant increase in density and hardness as the sintering temperature increased. The hardness increased from 4.65 GPa to 14.14 GPa, and the density increased from 4.70 to 5.97 (g/cm3) as the sintering temperature increased without changing the holding time. Sintering Ce-Y-TZP at 1600 °C produced samples with homogenous structures, high hardness (14.14 GPa), and full densification with 98% of the theoretical density.

Abstract: The paper presents the results of investigation on physical, mechanical and wear properties of SiC particulate reinforced aluminium metal matrix composite. The influence of reinforced ratios of 10, 15 and 20 wt. % of SiC_p on mechanical properties and wear characters was examined. The effect of load and sliding velocity on wear behavior of composite was studied. It was observed that increase of weight fraction of reinforcement produced better physical and mechanical properties such as density and hardness with 37 µm SiC reinforced composite inspite of increased density the hardness drops above the critical sintering temperature of 550°C due to crazing of the matrix. With increased size of SiC_p especially with higher temperature, density and hardness doesn’t supplement each other. Possible pooling/agglomeration in the case of medium and coarse sized reinforcement account for this. Wear decreases with increase in sintering temperature for 23 and 37 µm SiC_p reinforced composites where as it increases for 67 µm SiC_p reinforced composites. This could be attributed to formation of silanium compound contributing to discrete hardening of matrix. Wear tends to drop with sliding velocity being less contact between the pin and the disc but increases with normal load acting on the composite.