The Research of Gypsum Investment Mould Used as Forming Micro-Castings

2014 ◽  
Vol 609-610 ◽  
pp. 557-564
Author(s):  
Guo Tian Wang ◽  
Ming Xing Ren ◽  
Bang Sheng Li ◽  
Heng Zhi Fu
Keyword(s):  
Surface Roughness ◽  
Grain Size ◽  
Bending Strength ◽  
Sintering Temperature ◽  
Processing Parameters ◽  
Chemical Compositions ◽  
High Temperature And Pressure ◽  
Gypsum Content ◽  
Different Temperatures ◽  
Temperature And Pressure

By applying ultrasonic solidification, gypsum based micro casting mold with different chemical compositions were sintered at different temperatures. The influence of processing parameters and sintering temperature on the microstructure and surface roughness were investigated. Meanwhile, the effect of sintering temperature on the bending strength was studied. The result showed that the nucleation rate of gypsum can be significantly improved under high temperature and pressure, which was caused by the effect of ultrasonic cavitation. Under the frequency of 100 KHz and the power of 200 W, 20 min, the morphology of gypsum transfers from flake and needle into near spherical after 20 min, and the grain size can be refined to around 500 nm. The value node of surface roughness occurs at the sintering temperature of 600 °C. The surface roughness is the lowest when the gypsum content is 60% and under the sintering temperature of 600 °C, which can reach Ra ~ 0.22 um. The bending strength of mold roughly increased with the increase of content of gypsum. There is no obvious rule for the mold strength with the change of sintering temperature. The mold strength reaches the highest value when the sintering temperature is 600°C.

scholarly journals Influence of Various Process Parameters on the Density of Sintered Aluminium Alloys

10.14311/1604 ◽  
2012 ◽  
Vol 52 (4) ◽  
Author(s):  
Mateusz Laska ◽  
Jan Kazior
Keyword(s):  
Sintered Density ◽  
Sintering Temperature ◽  
Compaction Pressure ◽  
Nitrogen Atmosphere ◽  
Chemical Compositions ◽  
Green Density ◽  
Heating And Cooling ◽  
Wide Range ◽  
Different Temperatures ◽  
Metallurgy Industry

This paper presents the results of density measurements carried out on Alumix sintered parts. ECKA Alumix aluminium powders were used because of their wide application in the powder metallurgy industry. The compacts were produced using a wide range of compaction pressures for three different chemical compositions. The compacts were then sintered under a pure dry nitrogen atmosphere at three different temperatures. The heating and cooling rates were the same throughout the entire test. The results showed that the green density increases with compaction pressure, but that sintered density is independent of green density (compaction pressure) for each sintering temperature.

Effect of Annealing Atmosphere on the Morphology of Copper Oxide Thin Films Deposited on TiO2 Substrates Prepared by Sol-Gel Process

2013 ◽  
Vol 594-595 ◽  
pp. 113-117 ◽  
Author(s):  
Dewi Suriyani Che Halin ◽  
Ibrahim Abu Talib ◽  
Abdul Razak Daud ◽  
Muhammad Azmi Abdul Hamid
Keyword(s):  
Thin Films ◽  
Surface Roughness ◽  
Grain Size ◽  
Copper Oxide ◽  
Spin Coating ◽  
Sol Gel ◽  
Annealing Atmosphere ◽  
Oxide Thin Films ◽  
Different Temperatures ◽  
Xrd Patterns

Copper oxide films were prepared via sol-gel like spin coating starting from methanolic solutions of cupric chloride onto the TiO2 substrates. Films were obtained by spin coating under room conditions (temperature, 25-30 °C) and were subsequently annealed at different temperatures (200-400 °C) in oxidizing (air) and inert (N2) atmospheres. X-ray diffraction (XRD) patterns showed crystalline phases, which were observed as a function of the annealing conditions. The film composition resulted single or multi-phasic depending on both temperature and atmosphere. The grain size of film was measured using scanning electron microscopy (SEM) and the surface roughness of thin films was characterized by atomic force microscopy (AFM). The grain size of which was annealed in air at 300 °C was 30.39 nm with the surface roughness of 96.16 nm. The effects of annealing atmosphere on the structure and morphology of copper oxide thin films are reported.

Surface Roughness Scrutinizaton with RIE CF4+Argon Gaseous on Platinum Deposited Wafer

2014 ◽  
Vol 487 ◽  
pp. 71-74
Author(s):  
Zaliman Sauli ◽  
Vithyacharan Retnasamy ◽  
Aaron Koay Terr Yeow ◽  
Goh Siew Chui ◽  
K. Anwar ◽  
...  
Keyword(s):  
Surface Roughness ◽  
High Temperature ◽  
Influential Factor ◽  
Process Variables ◽  
Negative Effects ◽  
Working Pressure ◽  
Bias Power ◽  
High Temperature And Pressure ◽  
Temperature And Pressure ◽  
Controllable Process

Aluminium metallization has a disadvantage when it comes to high-end applications as it cannot withstand the high temperature and pressure. This paper studies the factors that affect the surface roughness on a Platinum deposited wafer after reactive ion etching (RIE) using a combination of CF4and Argon gaseous. A total of three controllable process variables, with 8 sets of experiments were scrutinized using a systematically designed design of experiment (DOE). The three variables in the investigation are ICP power, Bias power, and working pressure. The estimate of the effect calculated for ICP power, Bias power, and working pressure are-6.3608, -3.2858, and-5.394 respectively. All three factors gave negative effects. This implies that the surface roughness decreases when ICP power, Bias power, and working pressure is high. The ICP Power is the most influential factor followed by working pressure, and bias power.

On the Grain Size Distribution of MnO Doped ZnO Ceramics

2007 ◽  
Vol 336-338 ◽  
pp. 2361-2362
Author(s):  
Shu Ai Li ◽  
Da Nian Liu ◽  
Jiang Hong Gong
Keyword(s):  
Grain Size ◽  
Size Distribution ◽  
Grain Size Distribution ◽  
Sintering Temperature ◽  
Grain Morphology ◽  
Holding Time ◽  
Grain Sizes ◽  
Different Temperatures ◽  
Doped Zno ◽  
Zno Ceramics

A series of MnO-doped ZnO with different grain sizes and grain morphologies were prepared by sintering the samples at different temperatures for different holding times. The grain size distribution for each sample was determined. It was found that, although the grain size increases and the grain morphology varies with the sintering temperature and/or the holding time, the normalized grain size distribution keeps invariable.

Effect of Sintering Temperature on Properties of Multiferroic BaFe12O19/MgFe2O4/BaTiO3 Composites

2016 ◽  
Vol 846 ◽  
pp. 410-415
Author(s):  
M.F.A. Zolkepli ◽  
Rozidawati Awang ◽  
Zalita Zainuddin
Keyword(s):  
Grain Size ◽  
Solid State ◽  
Electrical Properties ◽  
Sintering Temperature ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Solid State Reaction Technique ◽  
Conventional Solid State Reaction ◽  
Different Temperatures ◽  
Tetragonal Batio

In this paper, the structural, magnetic and electrical properties of multiferroic BaFe12O19/MgFe2O4/BaTiO3 composites have been studied. BaFe12O19/MgFe2O4/BaTiO3 composites were synthesized by using the conventional solid state reaction technique and sintered at different temperatures. XRD analysis confirmed the existence of hexagonal BaFe12O19, cubic spinel MgFe2O4 and tetragonal BaTiO3 for ferrites and ferroelectric phases, respectively. The suitable sintering temperature for preparing BaFe12O19/MgFe2O4/BaTiO3 composites is between 1000 °C and 1050 °C. SEM analysis showed that as a whole the grain size increases and the pores is reduced with sintering temperature; thus the sample became denser. The coercive field and saturation magnetization decreases when sintering temperature is increased. Resistance of the samples decrease from 103 kW to 19 kW while the capacitance increases from 0.8 nF to 4.0 nF with sintering temperature.

MgAl2O4 Transparent Nano-Ceramics Prepared by Sintering under Ultrahigh Pressure

2007 ◽  
Vol 280-283 ◽  
pp. 549-552 ◽  
Author(s):  
Xiang Hui Chang ◽  
Tie Cheng Lu ◽  
Ying Zhang ◽  
Xiang Jie Luo ◽  
Qiang Liu ◽  
...  
Keyword(s):  
Grain Size ◽  
Low Temperature ◽  
Sintering Temperature ◽  
Ultrahigh Pressure ◽  
Transparent Ceramics ◽  
Grain Sizes ◽  
Average Grain Size ◽  
Temperature And Pressure ◽  
Sintering Characteristics ◽  
Sintering Condition

The first experimental work to produce transparent MgAl2O4 nano-ceramics was reported in this paper. The sintering characteristics of transparent nano-ceramics were investigated at relatively low temperature (800 ~ 1100°C) under ultrahigh pressure (2 ~ 5 GPa) using hydrostatic equipment. The morphologies and phases of ceramics were observed by means of SEM and XRD, respectively. The grain sizes of the ceramics are shown to be less than one hundred nanometers, far smaller than the sizes of common transparent ceramics. Furthermore, the higher the sintering temperature and pressure are, the greater the extent of densification is. At the same temperature, the higher the pressure is, the smaller the average grain size is. Under the same pressure, the higher the temperature is, the larger the average grain size is. The optimal sintering condition for preparing transparent nano-ceramics was also determined.

Microstructures and Mechanical Properties of Y2O3 Ceramics

2017 ◽  
Vol 726 ◽  
pp. 179-183
Author(s):  
Tong Yu Zhu ◽  
Jin Feng Xia
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Sintering Temperature ◽  
High Density ◽  
Average Grain Size ◽  
Basic Performance ◽  
Different Temperatures ◽  
Microstructures And Mechanical Properties

Currently, Y2O3 ceramics are widely used in various fields. The basic performance of Y2O3 ceramics were sintered temperatures are studied in this paper, their phase compositions and microstructure are studied with XRD and SEM. The mechanical properties of Y2O3 ceramics at different temperatures are studied. The sintering temperature of Y2O3 ceramic significantly affected the final grain size and density. It was found that a high density and fine average grain size of Y2O3ceramic can be simultaneously achieved when the sintering temperature was 1600°C. To determine the best sintering temperature, grain size, density, and mechanical properties were considered, and the most suitable sintering temperature was found to be 1600°C.

Nanopowder and Fine-Grained Ceramics for Multilayer PTCR Elements

2008 ◽  
Vol 368-372 ◽  
pp. 453-455 ◽  
Author(s):  
Jun Zhao ◽  
Shu Ping Gong ◽  
Chun Fang Cheng ◽  
Zhi Ping Zheng ◽  
Huan Liu ◽  
...  
Keyword(s):  
Grain Size ◽  
Sintering Temperature ◽  
Boundary Effect ◽  
Sol Gel ◽  
Tape Casting ◽  
Casting Technique ◽  
Fine Grained ◽  
Average Grain Size ◽  
Sol Gel Process ◽  
Different Temperatures

BaTiO3 nanopowders prepared by sol-gel process were used for multilayer PTCR ceramics in order to utilize grain boundary effect and lower sintering temperature. The precursor gel was calcined at different temperatures and the powders were characterized by XRD and TEM. The average grain size was about 26nm when calcined at 800°C for 2h. Effects of acceptor/donor concentration and sintering temperature on PTCR ceramics were also investigated. The optimal concentration of the donor was found to be 0.6mol with the acceptor concentration being 1/8 of the donor. Multilayer PTCR elements were fabricated by tape-casting technique. The jump ratio of PTCR chips sintered at 1240°C was above 103 with the average grain size smaller than 1~2 μm, which is suitable for the multilayer PTCR elements.

Surface Roughness and Wettability Correlation on Etched Platinum Using Reactive Ion Ecthing

2014 ◽  
Vol 487 ◽  
pp. 263-266 ◽  
Author(s):  
Zaliman Sauli ◽  
Vithyacharan Retnasamy ◽  
Aaron Koay Terr Yeow ◽  
Goh Siew Chui ◽  
K. Anwar ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Integrated Circuits ◽  
Inductively Couple Plasma ◽  
Great Influence ◽  
Wire Bonding ◽  
Thermal Coefficient ◽  
High Temperature And Pressure ◽  
Temperature And Pressure

As the world of semiconductor is moving towards smaller and high-end applications, the quality of the bonding adhesion for wire bonding is very critical. Although aluminium has been the metallization of choice in integrated circuits, it can be easily oxidized during high temperature and pressure. On the other hand, Platinum metallization layer has high thermal coefficient resistance and inert to oxygen. This paper reports the correlation between surface roughness and the wettability in the form of contact angle for Platinum deposited wafer etched using Inductively Couple Plasma-Reactive Ion Etching (ICP-RIE). Surface roughness was measured using AFM while contact angle was obtained via droplet test. The results clearly suggested that both surface roughness and wettabily, calculated by its contact angle value has the same trend. Surface roughness is directly proportional to the contact angle. This indicates that surface roughness have great influence on the surface wettability. Therefore, the adhesion for wire bonding process on platinum metallization which can be used in high end applications can be controlled by its surface roughness and wettability.

scholarly journals Environment-Friendly Preparation of Reaction-Bonded Silicon Carbide by Addition of Boron in the Silicon Melt

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1090
Author(s):  
Maoqiang Rui ◽  
Yaxiang Zhang ◽  
Jing Ye
Keyword(s):  
Mechanical Properties ◽  
Silicon Carbide ◽  
Bending Strength ◽  
Sintering Temperature ◽  
Argon Atmosphere ◽  
Environment Friendly ◽  
Silicon Melt ◽  
Different Temperatures ◽  
Carbide Ceramics ◽  
Silicon Carbide Ceramics

Reaction-bonded silicon carbide ceramics were sintered by infiltration of Si and B–Si alloy under an argon atmosphere at different temperatures. The element boron was added to the silicon melt to form a B–Si alloy first. The mechanical properties of samples were improved by infiltration of the B–Si melt. The samples infiltrated with the Si-only melt were found to be very sensitive to experimental temperature. The bending strengths of 58.6 and 317.0 MPa were achieved at 1530 and 1570 °C, respectively. The sample made by infiltration of B–Si alloy was successfully sintered at 1530 °C. The relative density of the sample was more than 90%. The infiltration of B–Si alloy reduced the sintering temperature and the bending strength reached 326.9 MPa. The infiltration mechanism of B–Si alloy is discussed herein.

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