scholarly journals Structure and Properties of Co-Cr-Mo Alloy Manufactured by Powder Injection Molding Method

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2010
Author(s):  
Grzegorz Matula ◽  
Aleksandra Szatkowska ◽  
Krzysztof Matus ◽  
Błażej Tomiczek ◽  
Mirosława Pawlyta
Keyword(s):  
Low Temperature ◽  
Injection Molding ◽  
Bending Strength ◽  
Ceramic Powder ◽  
Ethylene Vinyl Acetate ◽  
Powder Injection Molding ◽  
Powder Injection ◽  
Cobalt Chromium ◽  
Molding Method ◽  
Cobalt Chromium Molybdenum

Cobalt–chromium–molybdenum alloys samples were obtained by the powder injection molding method (PIM). PIM is dedicated to the mass production of components and can manufacture several grades of dental screws, bolts, stabilizers, or implants. As a skeleton component, ethylene–vinyl acetate (EVA copolymer) with a low temperature of processing and softening point was used. The choice of a low-temperature binder made it necessary to use a coarse ceramic powder as a mechanical support of the green sample during sintering. The injection-molded materials were thermally degraded in N2 or Ar-5%H2 and further sintered in N2-5%H2 or Ar-5%H2 at 1300 or 1350 °C for 30 min. The structure of the obtained samples was characterized by X-ray diffraction and electron microscopy. Mechanical properties, including hardness and three-point bending tests, confirmed that a nitrogen-rich atmosphere significantly increases the bending strength compared to the material manufactured in Ar-5%H2. This is due to the precipitation of numerous fine nitrides and intermetallic phases that strengthen the ductile γ-phase matrix.

Powder Injection Molding of Copper and the Effect of Sintering Temperature on Its Mechanical Properties

2010 ◽  
Author(s):  
Ali Keshavarz Panahi ◽  
Hossein Khoshkish
Keyword(s):  
Injection Molding ◽  
Copper Powder ◽  
Sintering Temperature ◽  
Powder Injection Molding ◽  
Powder Injection ◽  
Injection Molding Process ◽  
Capillary Rheometer ◽  
Molding Process ◽  
Molding Method ◽  
Different Temperatures

In this article, the fabrication steps of copper parts, using the powder injection molding method have been investigated. For the purpose of this study, first, several feedstocks were prepared by mixing copper powder (in volume percentages of 60, 64, 68, and 72%) and a thermoplastic binder. Due to the sensitivity of the mixing stage in the powder injection molding process, the Extrumixing method was utilized to appropriately mix the copper powder with the binder. Rheological characteristics of the different feedstocks were analyzed by means of a capillary rheometer. Based on this analysis, the feedstock having a 68 vol. % copper powder was selected as the optimum powder, out of which, samples shaped like tensile test specimens were successfully molded. These samples were later debinded by the solvent debinding method. Sintering of the pieces was carried out at different temperatures. Research showed that raising the sintering temperature leads to an increase of density and tensile strength of the specimens.

A Study of Ceramic Injection Molding of Watch Case Composed of ZrO2 Powder

2007 ◽  
Vol 534-536 ◽  
pp. 337-340 ◽  
Author(s):  
Te Su Kwak
Keyword(s):  
Computer Simulation ◽  
Injection Molding ◽  
Flow Pattern ◽  
Ceramic Powder ◽  
Weld Line ◽  
Powder Injection Molding ◽  
Powder Injection ◽  
Injection Molding Process ◽  
Molding Process ◽  
Inertia Effects

This study is focused on the manufacturing technique of powder injection molding of watch case made from zirconia powder. A series of computer simulation processes were applied to the prediction of the flow pattern in the inside of the mould and defects as weld-line. The material properties of melted feedstock, including the PVT graph and thermal viscosity flowage properties were measured to obtain the input data to be used in a computer simulation. Also, a molding experiment was conducted and the results of the experiment showed a good agreement with the simulation results for flow pattern and weld line location. On the other hand, gravity and inertia effects have an influence on the velocity of the melt front because of the high density of ceramic powder particles during powder injection molding in comparison with polymer’s injection molding process. In the experiment, the position of the melt front was compared with the upper gate and lower gate positions. The gravity and inertia effect could be confirmed in the experimental results.

Fabrication and Bending Strength of Al/SiC Composites with High Volume Fraction of Reinforcement by Combining Powder Injection Molding and Pressure Infiltration

2011 ◽  
Vol 189-193 ◽  
pp. 2945-2948
Author(s):  
Liang Xiong ◽  
Hao He ◽  
Yi Min Li
Keyword(s):  
Particle Size ◽  
Injection Molding ◽  
Bending Strength ◽  
Volume Fraction ◽  
High Volume ◽  
Powder Injection Molding ◽  
High Volume Fraction ◽  
Powder Injection ◽  
Pressure Infiltration ◽  
Sic Composites

The paper presents the result of an experimental investigation on the fabrication of Al/SiC composites with high volume fraction of SiC particles by pressure infiltration of liquid aluminum into preforms prepared by powder injection molding (PIM). To obtain the required high particle volume fraction, SiC powders with a bimodal particle size distribution were used. The influence of powder loading and particle size on the bending strength of the prepared composites has been investigated. It is demonstrated that pressure infiltration permits to achieve high relative densities for the composites (i.e. 98.8%). The microstructure studies revealed a uniform distribution of SiC particles in the composites without interface reactions between the particles and the aluminum matrix. The bending strength increases with increasing powder loading and decreasing particle size of the coarse powders in the bimodal powder system.

Low temperature powder injection molding of iron micro-nano powder mixture

2012 ◽  
Vol 228 ◽  
pp. 199-205 ◽  
Author(s):  
Woo-Kyung You ◽  
Joon-Phil Choi ◽  
Su-Min Yoon ◽  
Jai-Sung Lee
Keyword(s):  
Low Temperature ◽  
Injection Molding ◽  
Powder Mixture ◽  
Powder Injection Molding ◽  
Powder Injection ◽  
Nano Powder

Powder Injection Molding of Implantable Grade Materials

2006 ◽  
Author(s):  
Donald F. Heaney
Keyword(s):  
Stainless Steel ◽  
Injection Molding ◽  
Microelectromechanical Systems ◽  
Powder Injection Molding ◽  
Powder Injection ◽  
Technology Readiness ◽  
Prosthetic Replacement ◽  
Cobalt Chromium ◽  
Component Size ◽  
Chromium Alloys

In this paper the attributes of powder injection molding that influence the ability to implant a material are evaluated. Specific emphasis is given to technology readiness of stainless steel, titanium and cobalt chromium alloys since these are the most common alloys that are both implantable and metal injection moldable. Issues such as ductility and strengthening are discussed. Also, component size capability of the technology is discussed since prosthetic replacement pushes the upper size limit of the technology and implantable micro devices that require MEMS (MicroElectroMechanical Systems) scale features push the lower limit.

Investigation of Sintering Behaviors of Steatite Parts Produced by Powder Injection Molding

2007 ◽  
Vol 534-536 ◽  
pp. 549-552 ◽  
Author(s):  
Ibrahim Uslan ◽  
Mahmut Berber ◽  
Çetin Karatas ◽  
Suleyman Saritaş
Keyword(s):  
Injection Molding ◽  
Bending Strength ◽  
Linear Shrinkage ◽  
Powder Injection Molding ◽  
Powder Injection ◽  
Solid Loading ◽  
Heating Rates ◽  
Size Change ◽  
High Temperature Furnace ◽  
Different Temperatures

In this study, the properties of sintered parts produced by Powder Injection Molding (PIM) from the feedstocks of steatite powders with water based binders were investigated. The steatite powder solid loading was 58 vol. %. The properties investigated were density, % size change, tensile and bending strengths. Sintering in a high temperature furnace at different temperatures, heating rates and sintering times have been carried out. Densities of sintered parts have been measured by using Archimedes’ principle. Maximum attained relative density was 96 % at 1275 °C sintering temperature, 5 °C/min heating rate and 3 hours sintering time. At this sintering condition, linear shrinkage was 17.6 %, tensile strength was 16.7 MPa and bending strength was 130.6 MPa.

Applicability of different powder and polymer recipes in a new design powder injection molding system

2021 ◽  
Vol 41 (4) ◽  
pp. 299-309
Author(s):  
Bunyamin Cicek ◽  
Yavuz Sun ◽  
Yunus Turen ◽  
Hayrettin Ahlatci
Keyword(s):  
Injection Molding ◽  
Ethylene Vinyl Acetate ◽  
Powder Injection Molding ◽  
Polymer Composition ◽  
Powder Injection ◽  
New Production ◽  
Spherical Powder ◽  
Polymer Binders ◽  
Polymer Properties ◽  
Microstructure Examination

Abstract Production methods are changing day by day with the developing technology. Based on this idea, a new production logic and machine have been developed owing to polymer-supported powder injection molding (PIM). The ability of this newly designed machine (newPIM) to mold metal or ceramic powders supported by polymer binders is discussed in this study. By taking advantage of the polymer properties such as fluidity and sticking, powders are molded with a specially developed machine with high gas pressure in certain sizes. In this study, in which many parameters are processed from feedstock (FS) production to molding; metals Mg/316L and ceramics SiC/SiO2 powders have been used in different powder sizes and structures. In the newPIM process, polymers were included in four different recipes. Paraffin wax (PW), polyethylene glycol (PEG), polypropylene (PP), ethylene-vinyl acetate (EVA), poly-methyl methacrylate (PMMA) and low-density polyethylene (LDPE) have been employed in the FS with different combinations. From FS production to the molding stage; pressure, microstructure examination, weight loss, and density change features were investigated. The result indicated that the best FS and molding was obtained by the PEG+PMMA polymer composition formed with a spherical powder with a diameter below 40 µm. The compression force of the FS in this composition was observed at approximately 3.4k N values.

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