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.

Rheological Properties of Copper-Graphite MIM Feedstocks Prepared with Waste PET Binder

2014 ◽  
Vol 660 ◽  
pp. 209-213 ◽  
Author(s):  
Mohammad Fadhil Mat Nor ◽  
Safian Sharif ◽  
Khairur Rijal Jamaludin
Keyword(s):  
Shear Rate ◽  
Injection Molding ◽  
Rheological Properties ◽  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Metal Injection Molding ◽  
Injection Molding Process ◽  
Binder System ◽  
Molding Process ◽  
Capillary Rheometry

In this study, waste polyethylene terephthalate (PET) polymer binder systems were used to prepare copper-graphite metal injection molding (MIM) feedstock. A mixer and screw extrusion were used to achieve optimized feedstock, and the rheological properties of the resulting fluids were evaluated using a capillary rheometry to simulate the injection molding process. The solid loadings in the copper-graphite mixes were investigated in the ranges of 51-53% using PET binder system. The effects of shear rate (γ), solid volume fraction (φ) and temperature (T) on the rheological behavior of the copper/graphite MIM feedstocks are discussed.High viscosity trend was notably recorded as shear rate increased relatively. The results indicated that this feedstock system shows dilatant characteristic and lots of further work shall be conducted in attempt to establish this as an ideal binder system.

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.

Water Debinding for Zirconia Powder Injection Molding

2008 ◽  
Vol 368-372 ◽  
pp. 732-735 ◽  
Author(s):  
Zhi Peng Xie ◽  
Lin Lin Wang ◽  
Xian Feng Yang ◽  
Zhen Ting Zhang
Keyword(s):  
Polyethylene Glycol ◽  
Injection Molding ◽  
Powder Injection ◽  
Major Fraction ◽  
Zirconia Powder ◽  
Sintered Ceramic ◽  
Molecular Weights ◽  
Minor Fraction ◽  
Ceramic Injection Molding ◽  
A Minor

Water debinding is an important debinding technique for ceramic injection molding. However cracks or blisters usually generate during water extraction. In this paper, two types of multi-component binder systems were studied: (1) a major fraction of polyethylene glycol (PEG), and a minor fraction of polyvinyl butyra (PVB) and other additives. (2) a major fraction of PEG, and a minor fraction of polymethyl methacrylate (PMMA) and other additives. Mechanism of defects generation was investigated, and PEGs with various molecular weights were introduced to avoid cracks or blisters during the process. Further more, the compatibilities of PEG/PVB and PEG/PMMA were studied. The results showed that PEG and PMMA exhibited better compatibility, with the feedstock more homogeneous and sintered ceramic parts higher strength.

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.  

An Influence of a Binder System to the Rheological Behavior of the SS316L Metal Injection Molding (MIM) Feedstock

2011 ◽  
Vol 264-265 ◽  
pp. 554-558 ◽  
Author(s):  
Khairur Rijal Jamaludin ◽  
Norhamidi Muhamad ◽  
Hooman Abolhasani ◽  
Hadi Murthadha ◽  
Mohd Nizam Ab. Rahman
Keyword(s):  
Activation Energy ◽  
Shear Rate ◽  
Injection Molding ◽  
Rheological Behavior ◽  
Flow Behavior ◽  
Palm Stearin ◽  
Metal Injection Molding ◽  
Binder System ◽  
Flow Behavior Index ◽  
Injection Molded

The influence of a binder system to the rheological behavior of a Metal Injection Molding (MIM) feedstock is presented in the paper. The binder systems used are: a) PEG & PMMA b) Palm stearin & LLDPE and, c) Tapioca starch & LLDPE. The viscosity and shear rate of the feedstocks were measured at various range of temperature and shear rate across the L/D = 10 capillary rheometer. The flow behavior index, n and activation energy, E of each feedstock were measured to show its significance as MIM feedstock. Generally, the result indicates all feedstock exhibits a shear thinning behavior and the binders are suitable as MIM binder. Additionally, the present paper has discovered that the binder system does not have much influence to the activation energy. In order to show the relevance of the rheological behavior to the actual injection molding performance, green parts has been injection molded and the result shows an agreement with the rheological behavior result.

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.

scholarly journals The Technological Design of Geometrically Complex Ti-6Al-4V Parts by Metal Injection Molding

2019 ◽  
Vol 9 (7) ◽  
pp. 1339 ◽  
Author(s):  
Shulong Ye ◽  
Wei Mo ◽  
Yonghu Lv ◽  
Zhanhua Wang ◽  
Chi Tat Kwok ◽  
...  
Keyword(s):  
Injection Molding ◽  
Cost Effective ◽  
Metal Injection Molding ◽  
Binder System ◽  
Prealloyed Powder ◽  
Low Viscosity ◽  
Blended Powder ◽  
Complex Shapes ◽  
Thermal Debinding ◽  
Decomposition Behavior

In this study, the metal injection molding (MIM) process is applied to produce Ti-6Al-4V parts using blended and prealloyed powders, respectively. The feedstocks are prepared from a polyformaldehyde-based binder system with a powder loading of 60 vol%, exhibiting a low viscosity. The decomposition behavior of the binders is investigated and the thermal debinding procedure is designed accordingly. The debound parts are subsequently sintered at 1200 and 1300 °C. The results show the mechanical properties of the sintered samples prepared from blended powder are comparable to those prepared from prealloyed powder, with yield strength of 810 MPa, ultimate tensile strength (UTS) of 927 MPa, and elongation of 4.6%. The density of the as-sintered samples can reach 4.26 g/cm3 while oxygen content is ~0.3%. Based on the results, watch cases with complex shapes are successfully produced from Ti-6Al-4V blended powder. The case gives a good example of applying metal injection molding to mass production of precise Ti-6Al-4V parts with complex shapes in a cost-effective way.

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