Powder Injection Moulding Technology Research Articles

Structure and Properties of Ti3AlC2-SiC and Ti3AlC2-TiC Materials Obtained by Powder Injection Molding Technology

Powder injection melting (PIM) and material extrusion additive manufacturing (MEAM) are promising production technologies that allow us to obtain products from modern composite materials. These technologies make it possible to obtain products of complex shape from ceramic composite materials, which is a non-trivial task. A highly filled polymer feedstock is used as a source material in such technologies. In this work, a study of the structures and properties of samples obtained from SiC-Ti3AlC2 and TiC-Ti3AlC2 feedstocks by the PIM method was performed. The main purpose of this work was to study the influence of the powder compositions in feedstocks on the rheological properties and the structures of the obtained samples, as well as to determine the sintering parameters of samples of these compositions. In the future, it is planned to use the received and studied feedstocks in material extrusion additive manufacturing (MEAM). It was found that the investigated compositions had different MFI values depending on the composition. The effect of the sintering parameters on the structure and properties was shown. During the sintering of SiC-Ti3AlC2 ceramics in the temperature range of 1200–1400 °C in a vacuum, the main components of the mixture interacted with the formation of Ti3SiC2 and TiC. For materials of the TiC-Ti3AlC2 composition, partial oxidation of the material and the formation of titanium and aluminum oxides was observed.

Powder Injection Molding of Ti-Al-W Nano/Micro Bimodal Powders: Structure, Phase Composition and Oxidation Kinetics

Products from the materials of the Ti-Al system are difficult to manufacture. This often restricts the use of such materials despite their outstanding properties. Some of the promising methods for manufacturing products, which allows working with materials of the Ti-Al system, are powder injection molding (PIM) and material extrusion additive manufacturing (MEAM) technologies. In the present study, powder composites Ti-48Al-4W with different powder size distribution, obtained by the electric explosion of wire (EEW) method, were investigated. The powder was used in PIM technology to produce bulk samples. After polymer debinding, PIM samples were sintered in a vacuum and using hot isostatic pressing (HIP) at the same temperatures and isothermal holding times. The results show the influence of size distribution and sintering method on the structure, phase composition, mechanical properties and oxidation resistance of pre-sintered PIM samples. It is found that both the size distribution and sintering method affect the mechanical properties. The smaller the particle size of the powder in the material, the greater the resistance to oxidation of such samples.

Powder Injection Molding an Alternative Method in the Manufacturing of Parts for Vehicles

Powder injection molding (PIM) is one of the most versatile methods for manufacturing small complex shaped components from metal, ceramic powders for the use in many applications. Interesting applications of PIM include the automotive and aerospace industries. PIM can be used to combine multiple parts into a single part with complex geometry, and parts are lighter since porosity remains in the final part while the fatigue resistance increases. Therefore, it can be said that PIM can help reduce the weight of moving vehicles, which is a major concern from the environmental and economic point of view. One of the main limitations of current PIM technology is the long debinding time, which is one of the steps within the process. This has been partially solved by introducing binder systems that undergo catalytic sublimation. However, current catalytic binders have the main problem of high viscosity. In this study, two ways to decrease the viscosity of PIM feedstock materials with polyoxymethylene were investigated. The first way was to reduce the average molecular weight of the binder and the second one to select a polydisperse particle size distribution with high maximum packing fraction.

Time-Dependent Properties of Multimodal Polyoxymethylene based binder for Powder Injection Molding

Powder injection molding (PIM) is one of the most versatile methods for the manufacturing of small complex shaped components from metal, ceramic or cemented carbide powders for the use in many applications. PIM consists of mixing the powder and a polymeric binder, injecting this mixture in a mold, debinding and then sintering. Catalytic debinding of polyoxymethylene (POM) is attractive since it shows high debinding rates and low risk of cracking. This work examines the possibility of using bimodal POM as the main component of the binding agent by studying its time-dependent and thermal properties and comparing them to monomodal POM. Furthermore, possible optimization of the binder formulation was investigated by the addition of short molecular weight polymeric chains (wax) to bimodal POM, as to create a multimodal material. It was observed that the magnitude of the complex viscosity for the commercial bimodal material was more than 2 times lower than for the chemically identical monomodal POM within the investigated frequency range. Viscosity values were observed to drop as the content of wax was increased, without compromising thebinders mechanical properties in solid state. A new formulation of bimodal POM plus 8 wt.% of added wax provided the most appropriate results from investigated combinations. This work has shown how the addition of short polymeric chains in POM influences its time-dependent properties in solid and molten state, which can be an important tool for the optimization of binders designed to be used in PIM technology.

Rheology of Highly Concentrated Suspensions with a Bimodal Size Distribution of Solid Particles for Powder Injection Molding.

Powder injection molding (PIM) is one of the modern and prospective technologies in processing different materials. We proposed to use bimodal compositions of particles for increasing their content in the final products. A set of model suspension of Al with low-molecular-weight poly (ethylene glycol) as a binder based on theoretical arguments concerning the filling capacity of bimodal suspensions was prepared. Studying the rheological properties of these compositions showed that they demonstrate elasto-viscous behavior with significant plasticity that is favorable for the technological process. Using compositions with bimodal distributions allows for increasing the content of the solid phase up to 75 vol. % for PIM technology, which is significantly higher than the standard practical limit. This rheological approach developed for model formulations was applied to processing compositions containing aluminum oxide as typical ceramics and polyolefines as a binder widely used in technological practice. The obtained sintered ceramic samples have quite acceptable mechanical properties of the usual corundum articles.

Injection moulding of porous MAX phase Ti3SiC2 without using space-holder

Ti3SiC2 is one of the most studied MAX phase due to its unique combination of metallic and ceramic like properties. In this work, Powder Injection Moulding (PIM) is proposed as a new processing route to manufacture porous MAX phase Ti3SiC2, without the need of a space holder. The main goal of this work is to broaden MAX phase application fields through powder injection moulding technology. In depth characterization of all process stages has been done to control porosity in the final parts. Self-synthesized powders were mixed with a multicomponent binder for the production of sustainable feedstocks. The binder selection was carried out considering the design of a process with the reduction of the carbon footprint. In this sense, the binder consists of a combination of water soluble and low CO2 emission polymers. Feedstocks produced exhibit good properties for injection moulding. Critical solid loading (52 vol%) and a set of debinding debinding conditions has been determined for a two-step process without producing any defects in the samples. In addition, sintering parameters have been adjusted to successfully achieve porous MAX phase samples.

Process Parameters Used in Macro/Micro Powder Injection Molding: An Overview

Powder injection molding (PIM) is a well-known manufacturing technique for the production of complex, net-shaped macro-parts using a broad range of materials and alloys. Eventually, the PIM method has been modified into micro-powder injection molding (μPIM) because of the increasing demand of micro-parts in global market. Now-a-days PIM and μPIM processes are extensively using to fabricate components for electronic, automobile, and biomedical fields. In this paper, the important process parameters that had been used to fabricate defect-free macro and micro-sized parts of different metals, ceramics, and alloys using the above-mentioned techniques have been reviewed. This article is enclosed with a brief discussion on the future research guidelines addressing different aspects related to the two-component macro and micro powder injection molding. This paper could be a worthy source for those investigators who aim to work on PIM and μPIM technology.

Fabrication of WC-Co cutting tool by powder injection molding

In this work, a cutting tool for sand-mold milling was fabricated by powder injection molding (PIM) technology using 90WC-10Co alloy powder for machining sand molds in patternless sand-casting technology. The work included design of cutting tool tip, injection mold and binder system. Also, for the PIM process, mixing, injection molding, debinding and sintering process were investigated experimentally. Finally, the properties for final products were tested, such as micro structures, element composition, wear resistance and so on. The cutting tool fabricated by PIM had a final density of 14.21 g/cm3 (95% of theoretical density) and a dimension accuracy over 98%. Also, in sand-mold machining test, it showed an abrasion loss of 0.16 mm after working for 3 hrs. The results showed that a whole cutting tool was fabricated using PIM technology successfully, and it showed out good mechanical performances.

Powder injection moulding technology: Properties, possibilities and starting activities

Powder Injection Moulding (shortly PIM) enables a high-volume production of completely metal or ceramic complex geometry parts starting from non-completely metallic and ceramic materials, frequently plastic feedstock. Four phases of the PIM technology are described (compounding of feedstock, injection moulding of plastic binder/metal powder, debinding of binder component and sintering) based on the material consisting of thermoplastic binder and metal powder. A feedstock polyacetal binder/low alloy steel powder was chosen and by injection moulding technology the injection molded product, called a 'green part', is obtained. By this way, the 'green part' (precisely, test specimen according to the ASTM E8/E8M-11 standard) is produced in Serbia for the first time. A feedstock characteristics (density, semi-quantitative analysis and visual appearance) and 'green part 'properties (mass, density, semi-quantitative analysis and visual appearance) were tested. It was concluded that satisfactory results were obtained.

Holding Pressure and Its Influence on Quality in PIM Technology

The PIM (powder injection molding) process consists of several steps in which faults can occur. The quality of the part that is produced usually cannot be seen until the end of the process. It is therefore necessary to find a way to discover the fault earlier in the process. The cause of defects is very often “phase separation” (inhomogeneity in powder distribution), which can also be influenced by the holding pressure. This paper evaluates the powder distribution with a new method based on density measurement. Measurements were made using various holding pressure values.

Analysis and modeling of sintering of Sr-hexaferrite produced by PIM technology

The powder injection moulding (PIM) technology is lately becoming more and more significant due to complex design possibilities and good repeatability. This technology requires optimization of all steps starting with material and binder, injection, debinding and sintering parameters. Sintering is one of the key links in this technology. The powder injection moulding process is specific as during feedstock injection powder particles mixed into the binder do not come into mechanical contact. Shrinkage during sintering of PIM samples is high. In this work we have analyzed and modeled the sintering process of isotropic PIM samples of Sr-hexaferrite. The Master Sintering Curve (MSC) principle has been applied to analyze sintering of two types of PIM Sr-hexaferrite samples with completely removed binder and only the extraction step of the debinding procedure (thermal debinding proceeding simultaneously with sintering). Influence of the heating rate on resulting sample microstructures has also been analyzed. Influence of the sintering time and temperature was analyzed using three different phenomenological equations.

Recent advances in PIM technology I

In this article the state of art of the PIM (Powder Injection Moulding) technology is given in brief. The main process flow diagram consisting of four steps: feedstock preparation, injection moulding (green samples forming), the debinding (binder removing) procedure and the sintering process was described. After that the materials for binders and additives for the surface active agents were mentioned in brief. The metal injection moulding (MIM) process was analysed in more detail: MIM- stainless steels, MIM-copper and MIM-aluminium as the most metals common in MIM metal parts production. After that our results of MIM stainless steel 316 L and MIM copper are given. The main powder characteristics, the shrinkage and density of the sintered samples were compared for isostatically pressed PM (powder metallurgy) samples and MIM formed samples. The SEM fractographs of MIM and PM samples are given for MIM green parts, debinded (brown) parts and sintered parts, and PM green parts and sintered parts. The results obtained were compared with literature data before they were applied in metal parts production.

Recent advances in PIM technology I

In this article the state of art of the PIM (Powder Injection Moulding) technology is given in brief. The main process flow diagram consisting of four steps: feedstock preparation, injection moulding (green samples forming), the debinding (binder removing) procedure and the sintering process was described. After that the materials for binders and additives for the surface active agents were mentioned in brief. The metal injection moulding (MIM) process was analysed in more detail: MIM- stainless steels, MIM-copper and MIM-aluminium as the most metals common in MIM metal parts production. After that our results of MIM stainless steel 316 L and MIM copper are given. The main powder characteristics, the shrinkage and density of the sintered samples were compared for isostatically pressed PM (powder metallurgy) samples and MIM formed samples. The SEM fractographs of MIM and PM samples are given for MIM green parts, debinded (brown) parts and sintered parts, and PM green parts and sintered parts. The results obtained were compared with literature data before they were applied in metal parts production.

Recent advances in CIM technology

In this article the PIM (Powder Injection Moulding) technology is described in brief. After that the benefits and advantages were analyzed and summarized. Ceramic injection moulding (CIM) process was analyzed in more detail: CIM- alumina, CIM-zirconia and CIM ferrites as the most common technical ceramics in CIM ceramic parts production, medical applications and accessories in chemical laboratories, and cores in electronic inductive components. After that our results for CIM barium hexaferrite and piezo ceramics (barium titanate) are given. The main powder characteristics, the shrinkage and density and the main electrical characteristics of the sintered samples were compared for the isostatically pressed PM (powder metallurgy) and CIM formed samples. SEM fractographs of CIM and PM samples are given for CIM green parts, debinded (white) parts and sintered parts, and PM green parts and sintered parts. The results obtained were compared to literature data before they were applied in ceramic components production.

A net shape process for metallic microcomponent fabrication using Al and Cu micro/nano powders

This paper presents a new fabrication process for producing micro Al-based alloy components. The process is based on micro powder injection moulding technology, while the micromoulds are produced using MEMS technology. The process involves (1) fabrication of PDMS micromoulds from SU-8 masters, which are produced using a UV photolithography process; (2) making metallic paste by mixing 80 wt% of ultrafine Al (2.5 µm in average) powder, 5 wt% of Cu nanopowder (less than 60 nm), and 15 wt% of adhesive binder in about 30 ml of acetone; (3) mould filling with metallic paste and demoulding; and (4) sintering of the moulded component in an Ar atmosphere. The proposed process has been used to sinter Al–Cu powder microcomponents successfully without the help of either high pressure compression or mixing Mg with the Al powder. This research proposes a new approach to fabricate 3D micro metallic components to meet the needs in applications where metal, rather than silicon, microcomponents are required.

Rapid Manufacturing of Y-TZP Ceramic Punch Using Powder Injection Moulding Technology

Rapid Manufacturing of Y-TZP Ceramic Punch Using Powder Injection Moulding Technology

W-Cu의 마이크로 금속분말사출성형

The production of micro components is one of the leading technologies in the fields of information and communiation, medical and biotechnology, and micro sensor and micro actuator system. Microfabrication (micromachining) techniques such as X-ray lithography, electroforming, micromolding and excimer laser ablation are used for the production of micro components out of silicon, polymer and a limited number of pure metals or binary alloys. However, since the first development of microfabrication technologies there have been demands for the cost-effective replication in large scale series as well as the extended range of available material. One such promising process is micro powder injection molding (PIM), which inherits the advantages of the conventional PIM technology, such as low production cost, shape complexity, applicability to many materials, applicability to many materials, and good tolerance. This paper reports on a fundamental investigation of the application of W-Cu powder to micro metal injection molding (MIM), especially in view of achieving a good filling and a safe removal of a micro mold conducted in the experiment. It is absolutely legitimate and meaningful, at the present state of the technique, to continue developing the micro MIM towards production processes for micro components.

チタン合金の粉末射出成形・焼結技術

チタン合金の粉末射出成形・焼結技術

Molding of Meso Carbon Micro Beads by Powder Injection Molding Technology.

The applicability of powder injection molding technology to the molding of meso carbon micro beads was studied. The green bodies produced by injection molding of meso carbon micro beads were sintered after thermal debinding in oxidizing (air) and nonoxidizing (N2) atmospheres. For the sintered body debound thermally in a nonoxidizing atmosphere, the density and bending strength were 1.433 Mg/m3 and 20.25MPa, respectively. For the sintered body debound thermally in an oxidizing atmosphere, they were 1.304Mg/m3 and 2.39MPa, respectively. When the green bodies produced by injection molding of meso carbon micro beads were debound thermally in air, carbon powder contained in the green bodies was oxidized. Because of this, the sintered body which debound thermally in an oxidizing atmosphere exhibited low density and bending strength as compared to those of the sintered body which debound thermally in a nonoxidizing atmosphere. When a polyamide was used in the fabrication of meso carbon micro beads, the sintered density and bending strength were 1.770Mg/m3 and 42.62MPa, respectively.