Theory and practice of rapid and safe thermal debinding in ceramic injection molding

2019 ◽  
Vol 17 (3) ◽  
pp. 1098-1107 ◽  
Author(s):  
Hehan Xie ◽  
Jie Jiang ◽  
Xianfeng Yang ◽  
Qinglong He ◽  
Zhe Zhou ◽  
...  
2021 ◽  
Author(s):  
Yipeng ZHAO ◽  
Guoqing CHEN ◽  
Hongwei LI ◽  
Xuesong FU ◽  
Wenlong ZHOU

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.


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

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.  


2007 ◽  
Vol 561-565 ◽  
pp. 507-510
Author(s):  
Zhi Peng Xie ◽  
Lin Lin Wang ◽  
Xian Feng Yang

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.


Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1907 ◽  
Author(s):  
Jonas Biggemann ◽  
Patrizia Hoffmann ◽  
Ivaylo Hristov ◽  
Swantje Simon ◽  
Philipp Müller ◽  
...  

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.


2016 ◽  
Vol 13 (5) ◽  
pp. 838-843 ◽  
Author(s):  
Zhao Zhang ◽  
Yujun Zhang ◽  
Hongyu Gong ◽  
Xue Guo ◽  
Yubai Zhang ◽  
...  

2012 ◽  
Vol 2012 (1) ◽  
pp. 000604-000608
Author(s):  
Matthias Hartmann ◽  
Bertram Schmidt

The current research presents recent respective to the work development of a ceramic tubular probe for online substance concentration measurements. The aim was to develop a robust and acid-resistant sensor device, which can be easily included in existing procedural pipeline systems. To archive those goals a lot of factors had to be checked. For the substance concentration measurements a capacitive sensor effect was chosen. With this method even low substance concentrations down to one-tenth of a per cent can be indentified. For the package material zirconium oxide (tetragonal zirconia polycrystal – TZP) was used. Zirconium oxide is a technical ceramic which is wear-resistant, acid-resistant, has a low thermal conductivity, is electrically isolating and can be uses in a ceramic injection molding (CIM) process. In the phase of the sensor design process multiple geometries for the sensor effect and integration space for the evaluation electronics had to be considered. A standardized DN 10 DIN 32676 flanged joint was also added for an unproblematic connection to the pipelines. All these needed geometries had to be integrated into one ceramic element. As a result of these requirements a 3D CAD model of the sensor element was designed. The CAD-file has shown that there was only the CIM technology left to comprehend developed sensor geometry. CIM is a low cost process for large-scale production which is distinguished by high size accuracy. In the CIM process the material shrinkage, this is caused by the needed debindering and sintering steps, had to be considered. The developed ceramic tubular probe was successfully tested in multiple fluidic systems. It has left the test phase and is now ready for maturity phase.


Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1219 ◽  
Author(s):  
Anna Julia Medesi ◽  
Dorit Nötzel ◽  
Thomas Hanemann

The ceramic injection molding (CIM) process is a cost-effective powder-based near net shape manufacturing process for large-scale production of complex-shaped ceramic functional components. This paper presents the rheological analysis of environmentally friendly CIM feedstock formulations based on the binder components polyvinyl butyral (PVB) and polyethylene gycol (PEG). The prepared PVB/PEG-based alumina molding compounds were investigated with respect to their PVB:PEG ratios as well as to their powder filling degrees in the range between 50 and 64 vol.%. Corresponding viscosities and shear stresses were determined for increasing shear rates to show the effects of increased PEG content and solid loadings on them. Two single reactor components were injection molded and subsequently joined in their green state for fabrication of an alumina microreactor. The intended purpose of the alumina microreactors is their potential application as wear-resistant and hydrothermal stable multifunctional devices (µ-mixer, µ-reactor, µ-analyzer) for continuous hydrothermal synthesis (CHTS) of metal oxide nanoparticles in supercritical water (sc-H2O) as the reaction medium.


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