scholarly journals Rheological Behavior of Zirconia Added Alumina Mixture

2018 ◽  
Vol 7 (4.26) ◽  
pp. 251
Author(s):  
Siti Norazlini Abd Aziz ◽  
Wan Saiful Sarhan Wan Saidi ◽  
Mimi Azlina Abu Bakar ◽  
Muhammad Hussain Ismail
Keyword(s):  
Injection Molding ◽  
Heating Rate ◽  
Palm Stearin ◽  
High Hardness ◽  
High Strength ◽  
Hardness Test ◽  
Sintering Process ◽  
Ceramic Injection Molding ◽  
Thermal Debinding ◽  
Zirconia Toughened Alumina

Zirconia and alumina are one of the materials that is widely used in medical industry. Zirconia Toughened Alumina (ZTA) have great    properties to be apply in the ceramic injection molding such as have high hardness and high strength. The powder used in this research are alumina and zirconia while the binder to be used in this research is using 100% single based binder of palm stearin (PS). Behavior of zirconia blended alumina was investigated by rheological testing at temperature 55°C. Two formulations were used which is 60% (alumina/zirconia) plus 40% PS and 64% (alumina/zirconia) plus 36% PS. The ratio of alumina and zirconia used in this research is fixed at (85:15) for both samples. Four basic process involved which is mixing process, injection molding, thermal debinding and sintering     process has been implemented to complete ceramic injection molding (CIM). Sample were performed the thermal debinding at a heating rate 0.5°C/min up to 700°C and sintering at heating rate 3°C/min for temperature 1400°C and 1600°C. The hardness was tested using Rockwell hardness test for both AZ60 and AZ64 sample. Highest hardness was obtained from the sample AZ64 at the temperature 1600 °C which is 109HRR compare to the 1400°C that achieved 95.3HRR.  

Effect of Single Based Binder Palm Stearin on Sintered Properties of Hydroxyapatite Scaffold

2015 ◽  
Vol 763 ◽  
pp. 36-40 ◽  
Author(s):  
Siti Norazlini Abd Aziz ◽  
Mimi Azlina Abu Bakar ◽  
Ismail Muhammad Hussain
Keyword(s):  
Injection Molding ◽  
Ceramic Powder ◽  
Palm Stearin ◽  
Processing Temperature ◽  
Sintering Process ◽  
Fine Ceramic ◽  
Ceramic Injection Molding ◽  
Local Resources ◽  
Green Processing ◽  
Hydroxyapatite Scaffold

This paper reports on the compatibility of hydroxyapatite (HAP) combined with single based binder, palm stearin for ceramic injection molding in order to obtain the best properties. The feedstock was prepared at a powder loading of 62 Vol % using 5μm fine ceramic powder of hydroxyapatite and the binders consisting of 100% of palm stearin. The specimens underwent thermal de-binding and then sintered in an electrical furnace within a temperature range from 500°C to 1000°C. The resulting exhibit promising properties which the final product produced after the sintering process was successfully tested by mechanical testing. It is proven that even the specimen only consists of single based binder can form a complex shape without collapse just like the specimen obtained by the conventional binder system. Therefore, the fabrication also is more towards green processing technology and energy conservation due to the binder used was from natural local resources and used lower processing temperature at 50°C to 70°C for mixing and injection molding.

Thermal Debinding Process of SS 17-4 PH in Metal Injection Molding Process with Variation of Heating Rates, Temperatures, and Holding Times

2017 ◽  
Vol 266 ◽  
pp. 238-244 ◽  
Author(s):  
Sugeng Supriadi ◽  
Bambang Suharno ◽  
Rizki Hidayatullah ◽  
Gerra Maulana ◽  
Eung Ryul Baek
Keyword(s):  
Injection Molding ◽  
Heating Rate ◽  
Crack Formation ◽  
Holding Time ◽  
Effect Of Temperature ◽  
Metal Injection Molding ◽  
Injection Molding Process ◽  
Mass Reduction ◽  
Thermal Debinding ◽  
Debinding Process

Generally, metal injection molding (MIM) method utilizes SS 17-4 PH as material for application of orthodontic bracket. One of the process of MIM is thermal debinding, which binder is eliminated by thermal energy. In this study, thermal debinding process is conducted with variation of temperature, i.e. 480, 510, and 540°C, holding time, i.e. 0.5, 1 and 2 hours, heating rate, i.e. 0.5, 1, 1.5, and 2°C/min.The effect of temperature shows that the increased temperature will result in the mass reduction percentage due to formation of oxide on the sample, which will be proven through TGA testing. The highest mass reduction was 6.4137 wt% which was obtained at 480°C. For the variation of holding time, the longer the holding time will result in increased mass reduction and the highest mas reduction was 6.255 wt% which was obtained during 2 hours of holding time. For the heating rate, the slower the heating rate will result in increased mass reduction and decreased the presence of crack formation. The best variable was obtained at heating rate of 0.5°C/min, which resulted mass reduction of 6.2488 wt% and less crack formation.

scholarly journals Microstructure Evolution of (MgCoNiZnCu)O High Entropy Oxides Using Ceramic Injection Molding

2021 ◽  
Author(s):  
Yipeng ZHAO ◽  
Guoqing CHEN ◽  
Hongwei LI ◽  
Xuesong FU ◽  
Wenlong ZHOU
Keyword(s):  
Injection Molding ◽  
Injection Molding Process ◽  
Molding Process ◽  
High Entropy ◽  
Ceramic Injection Molding ◽  
Oxide Powders ◽  
Shaping Process ◽  
Thermal Debinding ◽  
Near Net Shaping ◽  
Net Shaping

Abstract Near net shaping ceramic injection molding process of (MgCoNiZnCu)O high entropy oxides were conducted using commercial precursor oxide powders. Through ball milling, internal mixing, injection molding, solvent and thermal debinding as well as final sintering process, the ceramic products would be obtained with little machining. Compacts prepared are single rock-salt phase based on XRD and EDS Mapping results. Meanwhile, with the increasing of sintering temperature from 900 ℃ to 1050 ℃, particle diffusion rate and densification of samples becomes faster, which finally results relative density and fractured strength of sintered compacts reaching the highest (90.47 % and 77.98 MPa, respectively) in current work. The successfully synthesis of (MgCoNiZnCu)O through ceramic injection molding illustrates this near net shaping process could be a promising route for preparation of high entropy oxides.

Experimental Investigation of Aluminium Hybrid Composites Reinforced with ZnS, TiO2 and BaTiO3 Produced Through Powder Metallurgy

2021 ◽  
Vol 13 (3) ◽  
Author(s):  
S. Rajeshkannan ◽  
I. Manikandan ◽  
M. Vigneshkumar
Keyword(s):  
Powder Metallurgy ◽  
Hybrid Composites ◽  
Brinell Hardness ◽  
High Hardness ◽  
High Strength ◽  
Hardness Test ◽  
Matrix Composites ◽  
X Ray Diffraction ◽  
Testing Instrument ◽  
X Ray

Semiconductors like ZnS, TiO2 and BaTiO3 were reinforced with Al-Al2O3 Metal Matrix Composites (MMCs) and were made through powder metallurgy in order to have high strength, high hardness and good thermal conductivity compared with conventional materials. Three MMC of test specimens were prepared with varying reinforcement ratio Al-Al2O3-ZnS(94-5-1), Al-Al2O3-TiO2(94-5-1), Al-Al2O3-BaTiO3(94-5-1) percentage by weight respectively. The hardness test has been made by using Brinell hardness testing instrument. Hardness test revealed that the addition of reinforcement TiO2, BaTiO3 increases the hardness value. However, the addition of ZnS to the Al-Al2O3 MMCs showed decrease in the hardness value. The crystal structure of the 3 composites were examined through X-Ray Diffraction (XRD) peaks.

scholarly journals Development of a WC-based cemented carbide using stainless steel as binder and titanium carbide

2021 ◽  
Author(s):  
Sara Fidelis Silva ◽  
Michel Picanço Oliveira ◽  
Márcia Giardinieri de Azevedo ◽  
Bárbara Ferreira de Oliveira
Keyword(s):  
Fracture Toughness ◽  
Stainless Steel ◽  
High Hardness ◽  
Hardness Test ◽  
Global Market ◽  
Cemented Carbides ◽  
Sintering Process ◽  
Hardness Tests ◽  
Different Temperatures ◽  
Spark Plasma

Cemented carbides belong to the most common and most important cutting tool materials, representing about half of the global market. To date, cemented carbides of the WC-Co system are preferred because they have an excellent combination of hardness, wear resistance and fracture toughness. However, substitutes for cobalt have been researched due to its toxicity, shortage and high cost. Promising results have shown that it is possible to achieve properties like the cemented carbides of the WC-Co system using stainless steels. In view of this, in this work a cemented carbides will be produced using WC, stainless steel, TiC and C. The addition of TiC is intended to inhibit the growth of grains at high temperatures, while C will be added to suppress the lack of carbon it takes to the formation of phases η. Samples will be manufactured using the spark plasma pulsed sintering process at different temperatures. From Archimedes' principle, the density of the samples and the densification promoted by each sintering temperature will be determined. Vickers microhardness and hardness tests will be carried out. Through indentation of the Vickers hardness test, the lengths of the cracks formed will be measured to determine the fracture toughness. It is expected, from this combination of components of the system, to produce a cemented carbides with high hardness, toughness and densification. The results of this work will be compared with data found in the literature to verify the feasibility of its use.

Study of Water-Debinding for Ceramic Parts by Injection Molding

2007 ◽  
Vol 561-565 ◽  
pp. 507-510
Author(s):  
Zhi Peng Xie ◽  
Lin Lin Wang ◽  
Xian Feng Yang
Keyword(s):  
Polyethylene Glycol ◽  
Shear Rate ◽  
Injection Molding ◽  
Bending Strength ◽  
Binder System ◽  
Ceramic Powders ◽  
Environment Friendly ◽  
Ceramic Injection Molding ◽  
Thermal Debinding ◽  
A New Technique

Water debinding is a new technique for ceramic injection molding. Compared with conventional thermal debinding, water-debinding has many advantages, such as environment friendly, high debinding rate, and suitable for molding large sized ceramic part. In this paper, binder system, based on polyethylene glycol(PEG) and polyvinyl butyryl(PVB), was mixed with 3Y-TZP(ZrO2) powder, and feedstock with 54vol% of ceramic powders was obtained. Shear viscosity of the feedstock was 300Pa·s at 190oC, when shear rate was 100/s, similar to the feedstock based on paraffin wax(PW). SEM showed that the feedstock and sintered parts were both homogeneous. Water debinding dynamics was also studied. For the 5mm x 6mm x 42mm sample, 65% of PEG could be extracted within 2 hours in water at 40oC, and the bending strength of sintered compacts was above 900MPa. The samples with thickness from 9mm to 12mm were made and the green parts could be debinded in water without any defects. The results showed water debinding method could increase the debinding rate and was effective to fabricate large sized ceramic parts.

scholarly journals Injection Molding of 3-3 Hydroxyapatite Composites

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1907 ◽  
Author(s):  
Jonas Biggemann ◽  
Patrizia Hoffmann ◽  
Ivaylo Hristov ◽  
Swantje Simon ◽  
Philipp Müller ◽  
...  
Keyword(s):  
Injection Molding ◽  
Patient Specific ◽  
Pore Former ◽  
Porous Hydroxyapatite ◽  
Pore Networks ◽  
Ceramic Injection Molding ◽  
Thermal Debinding ◽  
Near Net Shape ◽  
Urethane Dimethacrylate ◽  
Interconnected Pore

The manufacturing of ideal implants requires fabrication processes enabling an adjustment of the shape, porosity and pore sizes to the patient-specific defect. To meet these criteria novel porous hydroxyapatite (HAp) implants were manufactured by combining ceramic injection molding (CIM) with sacrificial templating. Varied amounts (Φ = 0–40 Vol%) of spherical pore formers with a size of 20 µm were added to a HAp-feedstock to generate well-defined porosities of 11.2–45.2 Vol% after thermal debinding and sintering. At pore former contents Φ ≥ 30 Vol% interconnected pore networks were formed. The investigated Young’s modulus and flexural strength decreased with increasing pore former content from 97.3 to 29.1 GPa and 69.0 to 13.0 MPa, agreeing well with a fitted power-law approach. Additionally, interpenetrating HAp/polymer composites were manufactured by infiltrating and afterwards curing of an urethane dimethacrylate-based (UDMA) monomer solution into the porous HAp ceramic preforms. The obtained stiffness (32–46 GPa) and Vickers hardness (1.2–2.1 GPa) of the HAp/UDMA composites were comparable to natural dentin, enamel and other polymer infiltrated ceramic network (PICN) materials. The combination of CIM and sacrificial templating facilitates a near-net shape manufacturing of complex shaped bone and dental implants, whose properties can be directly tailored by the amount, shape and size of the pore formers.

Sign in / Sign up

Export Citation Format

Share Document