Ti–6Al–4V alloy cortical bone screw production by powder injection molding method

2017 ◽  
Vol 7 (4) ◽  
pp. 245-252 ◽  
Author(s):  
Levent Urtekin ◽  
Anıl Taşkın
Author(s):  
Ali Keshavarz Panahi ◽  
Hossein Khoshkish

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.


2014 ◽  
Vol 49 (24) ◽  
pp. 8234-8243 ◽  
Author(s):  
Andreas Reindl ◽  
Rouven Borowsky ◽  
Sebastian Boris Hein ◽  
Juergen Geis-Gerstorfer ◽  
Philipp Imgrund ◽  
...  

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2010
Author(s):  
Grzegorz Matula ◽  
Aleksandra Szatkowska ◽  
Krzysztof Matus ◽  
Błażej Tomiczek ◽  
Mirosława Pawlyta

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.


2020 ◽  
Author(s):  
Elena Glazkova ◽  
Nikolay Rodkevich ◽  
Nikita Toropkov ◽  
Aleksandr Pervikov ◽  
Marat Lerner

2010 ◽  
Vol 103 (4) ◽  
pp. 1145-1151 ◽  
Author(s):  
L. Liu ◽  
N. H. Loh ◽  
B. Y. Tay ◽  
S. B. Tor ◽  
H. Q. Yin ◽  
...  

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Fouad Fareh ◽  
Vincent Demers ◽  
Nicole R. Demarquette ◽  
Sylvain Turenne ◽  
Orlando Scalzo

The impact of binders and temperature on the rheological properties of feedstocks used in low-pressure powder injection molding was investigated. Experiments were conducted on different feedstock formulations obtained by mixing Inconel 718 powder with wax-based binder systems. The shear rate sensitivity index and the activation energy were used to study the degree of dependence of shear rate and temperature on the viscosity of the feedstocks. The injection performance of feedstocks was then evaluated using an analytical moldability model. The results indicated that the viscosity profiles of feedstocks depend significantly on the binder constituents, and the secondary binder constituents play an important role in the rheological behavior (pseudoplastic or near-Newtonian) exhibited by the feedstock formulations. Viscosity values as low as 0.06 to 2.9 Pa·s were measured at high shear rates and high temperatures. The results indicate that a feedstock containing a surfactant agent exhibits the best moldability characteristics.


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