Defect Analysis of 316LSS during the Powder Injection Moulding Process

2012 ◽  
Vol 329 ◽  
pp. 35-43 ◽  
Author(s):  
M. Rafi Raza ◽  
Faiz Ahmad ◽  
M.A. Omar ◽  
R.M. German ◽  
Ali S. Muhsan
Keyword(s):  
Solvent Extraction ◽  
Complete Removal ◽  
Processing Parameters ◽  
Powder Injection ◽  
Extraction Temperature ◽  
Heating Rates ◽  
Process Step ◽  
Moulding Process ◽  
Aerospace Applications ◽  
Injection Moulding Process

Austenitic Stainless Steel Has a FCC Structure at Room Temperature and the Temperature Range of the Austenite Phase Depends upon its Composition. 316L SS Is Widely Used in Medical, Marine, Industrial, Sporting and Aerospace Applications due to its Excellent Combination of Mechanical Properties and Corrosion Resistance. this Study Presents the Defects Observed during Optimization of the Processing Parameters for the Fabrication of Powder Injection Molding (PIM) of 316L SS Parts. in this Study, Five Formulations of Feedstock Containing 60-71vol% of Metal Powder Were Prepared Using a Wax-Based Binder. Green Samples Were Injection-Moulded, Followed by Binder Removal by Solvent and Thermal Means. Paraffin Wax (major Binder) Was Extracted at Various Temperatures in Order to Determine the Solvent Extraction Temperature. the Thermal De-Binding Was Performed Successfully at a Temperature of 450°C by Varying the Heating Rate from 1°C/min -10°C/min. SEM Results Showed Complete Removal of the Plastic Binder. Test Samples Were Sintered at Various Temperatures and Atmospheres. the Defects Observed during Solvent Extraction Were Swelling, Cracks and, at the Thermal De-Binding Step, Collection of Binder, Swelling and Holes. Sintered Samples Showed a Loss of Dimensional Control. these Types of Defect Were Considered to Be due to Inappropriate Heating Rates, Temperature and Dwell Time at each Process Step.

Effects of Complexing Agent Concentration and Bath pH on Electroless Nickel Deposition for Tungsten Carbide Powders

2014 ◽  
Vol 970 ◽  
pp. 240-243 ◽  
Author(s):  
Pranee Rattanawaleedirojn ◽  
Kanokwan Saengkiettiyut ◽  
Yuttanant Boonyongmaneerat ◽  
Nutthita Chuankrerkkul ◽  
Sawalee Saenapitak
Keyword(s):  
Tungsten Carbide ◽  
Deposition Rate ◽  
Electroless Nickel ◽  
Powder Injection ◽  
Complexing Agent ◽  
Chemical Compositions ◽  
High Deposition Rate ◽  
Nickel Deposition ◽  
Moulding Process ◽  
Injection Moulding Process

An elemental nickel (Ni) or cobalt (Co) is typically introduced to tungsten carbide (WC) prior to powder injection moulding process (PIM) for hard metal fabrication to enhance toughness and tool life. Mixing of powders is normally practiced, although it requires a long processing time for homogeneous mixing. In this study, as an alternative method, an addition of Ni via the electroless deposition method is investigated. The key process parameters, including the concentration of the complexing agent, namely sodium citrate, and bath pH, are systematically examined in relation to deposition rate and deposits size, microstructure, and chemical compositions. As the bath pH is increased to higher alkalinity of 10 and the Ni ion to complexing agent mole ratio is controlled under 1:1, a stable electroless nickel solution and a relatively high deposition rate with about 15% weight gain for 1 hour deposition duration are achieved. The phosphorus (P) content, obtained in the range of 5-9 wt%, is largely influenced by the bath pH. While a rapid deposition rate is associated with preferentially deposition of Ni on pre-deposited Ni sites, a low to moderately high deposition rate results in more uniform incorporation of Ni-P alloys in WC powder mixture.

scholarly journals Optimisation of Mould Design for Injection Moulding – Numerical Approach

2021 ◽  
Vol 15 (2) ◽  
pp. 258-266
Author(s):  
Damir Godec ◽  
Vladimir Brnadić ◽  
Tomislav Breški
Keyword(s):  
Computer Simulation ◽  
Injection Moulding ◽  
Numerical Approach ◽  
Processing Parameters ◽  
Simulation Software ◽  
Moulding Process ◽  
Part Geometry ◽  
Injection Moulding Process ◽  
Mould Cavity ◽  
Mould Design

Computer simulation of injection moulding process is a powerful tool for optimisation of moulded part geometry, mould design and processing parameters. One of the most frequent faults of the injection moulded parts is their warpage, which is a result of uneven cooling conditions in the mould cavity as well as after part ejection from the mould and cooling down to the environmental temperature. With computer simulation of the injection moulding process it is possible to predict potential areas of moulded part warpage and to apply the remedies to compensate/minimize the value of the moulded part warpage. The paper presents application of simulation software Moldex 3D in the process of optimising mould design for injection moulding of thermoplastic casing.

scholarly journals Modeling and Analysis of Injection Moulding Process Parameters for Plastic Gear Industry Application

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Nik Mizamzul Mehat ◽  
Shahrul Kamaruddin ◽  
Abdul Rahim Othman
Keyword(s):  
Polymer Melt ◽  
Optimization Method ◽  
Processing Parameters ◽  
Taguchi Optimization ◽  
Modeling And Analysis ◽  
Moulding Process ◽  
Real Process ◽  
Injection Moulding Process ◽  
Mould Design ◽  
Plastic Gears

The performance of plastic gears in wide variety of power and motion transmission applications is rather limited due to weak mechanical properties and divergent mechanism of failures. A methodical simulation is carried out to analyze the gear performance with various gating system types, gate locations, and processing parameters via grey-based Taguchi optimization method. With the obtained optimum results in simulation stage, the flow patterns of polymer melt inside the mould during filling, packing, and cooling processes are studied and the plastic gear failures mechanism related to processing parameters are predicted. The output results in the future can be used as guidance in selecting the appropriate materials, improving part and mould design, and predicting the performance of the plastic gear before the real process of the part manufacturing takes place.

Properties of Porous Alumina Fabricated by Ceramic Injection Moulding Using Environmentally Friendly Binder

2012 ◽  
Vol 506 ◽  
pp. 238-241 ◽  
Author(s):  
J. Surawatthana ◽  
Nutthita Chuankrerkkul ◽  
Wantanee Buggakupta
Keyword(s):  
Injection Moulding ◽  
Porous Alumina ◽  
Polyvinyl Butyral ◽  
Powder Injection ◽  
Water Leaching ◽  
Moulding Process ◽  
Powder Injection Moulding ◽  
Injection Moulding Process ◽  
Thermal Debinding ◽  
Ceramic Injection Moulding

Porous alumina (Al2O3) ceramics were fabricated by powder injection moulding process. The feedstocks, composed of 44 50 vol% of Al2O3 powder, could be prepared using a composite binder, consisting of polyethylene glycol (PEG) and polyvinyl butyral (PVB). Debindings were carried out using a combination of water leaching of the PEG and thermal debinding of the PVB. It was observed that the removal of the PEG was fast at the initial stage and more than 90 wt% of the PEG could be removed within 4 hours. Sintering was performed in argon atmosphere at 1600 °C. The sintered specimens had apparent porosity in range of 26-32 %, depending on the feedstock compositions. The flexural strength values were in range of 90-140 MPa while the hardness values were in range of 5-9 GPa. It was found that both the strength and hardness of the specimens were increased with increasing powder loading.

Influence of mould material on ceramic disc dimensions in low-pressure injection moulding

2016 ◽  
Vol 231 (1-2) ◽  
pp. 187-195 ◽  
Author(s):  
Carlos A Costa ◽  
Carlos R Altafini ◽  
Fabio R Visioli ◽  
André P Baccin
Keyword(s):  
Cooling Rate ◽  
Injection Moulding ◽  
Low Pressure ◽  
Extraction Temperature ◽  
Mould Insert ◽  
Mould Material ◽  
Moulding Process ◽  
Pressure Injection ◽  
Injection Moulding Process ◽  
Geometric Deviations

This work presents a study regarding the influence of the cooling process, as a result of different mould insert materials, on ceramic parts dimensions obtained by low-pressure injection moulding process. Discs of ceramic with Ø80 × 2 mm, composed by 86 wt.% alumina (Al2O3) and 14 wt.% organic vehicle, were produced. An experimental injection mould was designed and manufactured with built-in heating and cooling systems, controlled by a DAQ (Measurement Computing – USB-TC) and thermocouples K type. Four types of insert materials were used: aluminium alloy (AA7075-T6), electrolytic copper, brass alloy (C36000) and SAE1045 steel. Tests were carried out considering injection moulding parameters constant, i.e. initial mould temperature, injection pressure and time and extraction temperature. All the post-process (debinding by wicking; final debinding and sintering) parameters were also kept constant. Parts were analysed considering dimensions, mass, geometry, visual aspects and defects. The results showed that the cooling rate resulting from the thermal conductivity of each material has influenced more significantly the dimensional shrinkage and mass reduction of the samples during the intermediate post-processes phases. The geometric deviations were different for each condition throughout the process and they increased in the final parts. The parts produced with higher cooling rate had higher geometric deviations.

scholarly journals Problems and Constraints Involved in the Injection Moulding Process of Biocomposites: A Review

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Mohd Khairul Fadzly Md Radzi ◽  
Norhamidi Muhamad ◽  
Abu Bakar Sulong ◽  
Nabilah Afiqah Mohd Radzuan ◽  
Mohd Ramdhan Mohd Khalid ◽  
...  
Keyword(s):  
Injection Moulding ◽  
Early Stage ◽  
Processing Parameters ◽  
Moulding Process ◽  
Injection Moulding Process ◽  
Mixing Method ◽  
Manufacturing Applications ◽  
Feedstock Preparation ◽  
Biocomposite Material

Biocomposite materials have revolutionized the engineering field, predominantly in manufacturing applications, where these materials were widely used as an alternative to the metal-based structural body or component. Since conventional materials have caused various pollution problems to the ecosystem, innovative efforts have been taken to develop the based product on natural materials composites but presently are not fully explored yet. Most issues raised are due to the lack of expertise in addressing some of the problems and constraints related to preparing feedstock materials involved in the injection moulding technique. The injectability process of the biocomposite material significantly depends on the early stage of feedstock preparation. The preparation steps should be considering the detailed characterization of the composite material, the effectiveness of the mixing method, the identification of the feedstock's flowability properties, and the appropriate processing parameters used. This review manuscript has a significant contribution to researchers interested in furthering the application of biocomposite-based materials, particularly in plastics injection moulding technology for manufacturing and processing engineering.

Sign in / Sign up

Export Citation Format

Share Document