Princeton, NJ, United States
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Shivashankar T.S.,Indo-MIM | Enneti R.K.,Global Tungsten Powders | Park S.-J.,Pohang University of Science and Technology | German R.M.,San Diego State University | Atre S.V.,Oregon State University
Powder Technology | Year: 2013

The composition of the powder-binder mixture (feedstock) used in powder injection molding (PIM) plays a crucial role in fabricating defect-free parts. Powder-binder separation in the feedstock during mixing or molding is responsible for defects such as voids, cracks, or distortion in the sintered part. This study introduces an inter-particle spacing parameter, δ, based on particle size (D), particle volume fraction (φ) and maximum particle fraction (φm). The derived parameter is investigated using feedstocks prepared from three different metal powders. Based on comparisons with experimental data from this study as well as reports in the literature, the inter-particle spacing parameter, δ, proves to be a useful predictor of powder-binder separation. The newly proposed parameter assists in designing and developing feedstocks to manufacture components by PIM. © 2013 Elsevier B.V.

Enneti R.K.,Global Tungsten Powders | Shivashankar T.S.,Indo-MIM | Park S.-J.,Pohang University of Science and Technology | German R.M.,San Diego State University | Atre S.V.,Oregon State University
Powder Technology | Year: 2012

This study successfully extends the master sintering curve concept to model removal of polymeric binders in powder injection molded bodies. In this demonstration the focus is solvent debinding. Master debinding curves (MDC) were used to estimate the activation energy for debinding. Binder removal curves were developed for solvent extraction of polyethylene glycol (PEG) from injection molded shapes made from silicon nitride doped with yttria and spinel (Si 3N 4 5% Y 2O 3 5% MgAl 2O 4). The extraction for different shapes incorporated a shape parameter in the standard master curve equation, giving activation energy of 12.4kJ/mol extraction of PEG. Master debinding curves were also developed for wicking debinding. The analysis showed lower activation energies for solvent extraction and wicking compared to thermal debinding. The lower activation energy suggests easier removal by solvent or wicking versus pyrolysis. The study provides a unifying quantitative framework for comparing and predicting the effects of material, process and geometry on binder removal. The master debinding curves can be utilized in design and optimization of binder removal. © 2012.

Mukund B.N.,Indo-MIM | Hausnerova B.,Tomas Bata University in Zlin | Shivashankar T.S.,Indo-MIM
Powder Technology | Year: 2015

Design of a powder injection molding (PIM) feedstock with proper selection of powder with unique particle size, particle shape and solid loading plays a significant role in controlling defects and distortion of PIM products. Using the concept of "interparticle spacing/volume fraction of lubricating liquid" 17-4PH stainless steel feedstocks with various bimodal powder combinations in thermoplastic polymer binder were designed and evaluated using both capillary and torque rheometers. Tendency to powder-binder separation, which is a factor indicating unacceptable distortions of sintered parts, is determined from the density variance during time-dependent viscosity measurement and thresholds in volume fraction of lubricating liquid as well as interparticle spacing parameters. The tailored feedstock with an optimum bimodal powder combination of coarse and fine particles exhibits suitable rheological performance with no evidence of separation and limited sintering distortion. © 2015 Elsevier B.V.

Mukund B.N.,Indo-MIM | Shivashankar T.S.,Indo-MIM
Advances in Powder Metallurgy and Particulate Materials - 2014, Proceedings of the 2014 World Congress on Powder Metallurgy and Particulate Materials, PM 2014 | Year: 2014

An attempt has been made to arrive at the feedstock with optimum bimodal powder combination which exhibit best rheological properties with no molding defects and least sintering distortion among the chosen powder combinations. The study is also aimed at reducing the cost of the feedstock using various combinations of courser and finer particles and improving the deformation resistance of the compact after sintering. Feedstocks were prepared by mixing a bimodal powder combination with a thermoplastic polymer binder system. The design of feedstock with proper selection of powder with unique particle size, shape and solid loading plays a significant role in controlling defects and distortion in PIM products. Using an already proven concept of "Interparticle spacing" and "volume fraction of lubricating liquid" which is used to arrive at optimum powder loading for mono-disperse feedstocks, 17-4PH Stainless Steel (SS) feedstocks with various bimodal powder combinations were designed and evaluated for best performance in PIM. Capillary Rheometer and Torque Rheometer were used to evaluate homogeneity, stability of the feedstock against powder-binder separation.

Mukund B.N.,Indo-MIM | Shivashankar T.S.,Indo-MIM
International Powder Metallurgy Congress and Exhibition, Euro PM 2013 | Year: 2013

The powder-binder composition in a feedstock used for powder injection molding (PIM) plays a crucial role in manufacturing distortion free products out of sintering. This study successfully demonstrates the application of 'interparticle spacing parameter, δ' to model shape retention (distortion) of a powder injection molded (PIM) feedstocks in sintering. The powders used in the study are Carbonyl iron powder with 2% Ni (CIP), Cobalt based Co-400 (Co-400) and 17-4PH Stainless Steel (SS) alloying composition. 'Interparticle spacing parameter, δ' of CIP, Co-400 and 17-4PH SS powder differing in powder morphology and mean particle size was investigated. The binder system considered for the study is wax-polymer system. The experimental data from this study, suggests the 'interparticle spacing parameter, δ', proves to be a useful predictor of shape retention of PIM components. The reports in the literature and also based on the experimental data in the present work using Capillary Rheometer and Pycnometer the 'Interparticle spacing parameter, δ' is also a useful predictor of powder-binder separation. An optimum region has been proposed which assists in designing defects and distortion free feedstock formulation right at first time to manufacture components by PIM without resorting to trial-and-error practices currently prevalent in the industry.

Mukund B.N.,Indo-MIM | Shivashankar T.S.,Indo-MIM | Sachin M.,Indo-MIM
Advances in Powder Metallurgy and Particulate Materials - Proceedings of the 2015 International Conference on Powder Metallurgy and Particulate Materials, PowderMet 2015 | Year: 2015

Selection of the suitable material in Metal Injection Molding (MIM) technology play a significant role in manufacturing durable MIM products to meet customer expectations. The recent tremendous growth in consumer electronics industry with the introduction of cell phones, smartwatches, wearable electronic devices, laptops and tablets have demonstrated the advantage of MIM technology in manufacturing highly complex designed parts with tight tolerances at competitive price compared to other alternate manufacturing technologies. Most of these applications in consumer electronic devices require a high gloss metallic texture or mirror finish and appropriate strength for protection. Different Stainless steel (SS) materials are evaluated to understand the critical parameters involved in obtaining a mirror finish on the MIM metal components. Properties of Stainless Steel materials like chemical composition, density, surface porosity and hardness were discussed in correlation with mirror finished surface on a watchcase MIM product used in consumer electronic application.

Indo-MIM | Entity website

Hindistan, Bangalorede bulunan Indo-MIM, ekirdek retim teknolojisi olarak, metal enjeksiyon kalplama (MIM) tekniini kullanarak hassas mhendislik rnlerinin, dnya lideri tedarikisidir. MIM prosesi, plastik enjeksiyon kalplama tekniinin esnekliiyle dvme metalin mukavemetinin bir kombinasyonu olarak ok kompleks para geometrileri iin ekonomik zmler sunar ...

Indo-MIM | Entity website

Indo-MIM in Bangalore, Indien, ist ein weltweit fhrender Anbieter fr przisionsgefertigte Produkte im Metallpulverspritzguss (MIM) als Kerngeschft. Das MIM Verfahren vereint die Design-Flexibilitt des Kunststoffspritzgusses mit der Festigkeit von gewalztem Stahl, um kostengnstige Lsungen fr hochkomplexe Teilegeometrien anbieten zu knnen ...

Indo-MIM | Entity website

Indo-US MIM Tec Pvt. Ltd ...

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