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A new wire arc additive manufacturing (WAAM) process combined with gravity-driven powder feeding was developed to fabricate components of tungsten carbide (WC)-reinforced iron matrix composites. The purpose of this study was to investigate the particle transportation mechanism during deposition and determine the effects of WC particle size on the microstructure and properties of the so-fabricated component.

Thin-walled samples were deposited by the new WAAM using two WC particles of different sizes. A series of in-depth investigations were conducted to reveal the differences in the macro morphology, microstructure, tensile performance and wear properties.

The results showed that inward convection and gravity were the main factors affecting WC transportation in the molten pool. Large WC particles have higher ability than small particles to penetrate into the molten pool and survive severe dissolution. Small WC particles were more likely to be completely dissolved around the top surface, forming a thicker region of reticulate (Fe, W)₆C. Large WC particles can slow down the inward convection more, thereby leading to an increase in width and a decrease in the layer height of the weld bead. The mechanical properties and wear resistance significantly increased owing to reinforcement. Comparatively, samples with large WC particles showed inferior tensile properties owing to their higher susceptibility to cracks.

Fabricating metal matrix composites through the WAAM process is a novel concept that still requires further investigation. Apart from the self-designed gravity-driven powder feeding, the unique aspects of this study also include the revelation of the particle transportation mechanism of WC particles during deposition.

Laser powder bed fusion (LPBF) can be used to fabricate complex extrusion die without the limitation of structures. Layer-by-layer processing leads to differences in microstructures and wear properties. This study aims to investigate the microstructure evolution and effects of tungsten carbide (WC) on the wear properties of LPBF-printed 18Ni300.

Economical spherical granulation-sintering-deoxygenation (GSD) WC-reinforced 18Ni300 steel matrix composites were produced by LPBF from powder mixtures of WC and 18Ni300. The effects of WC contents on anisotropic microstructures and wear properties of the composites were investigated.

The relative density is more than 99% for all the composites except 25% WC/18Ni300 composite. The grain sizes distributed on the top cross-section are smaller than those on the side cross-section. After adding WC particles, more high-angle grain boundaries and larger Schmid factor generate, and deformed grains decrease. With increasing WC contents, the hardness first decreases and then increases but the wear volume loss decreases. The side cross-section of the composite has higher hardness and better wear resistance. The 18Ni300 exhibits adhesive wear accompanying with abrasive wear, while plowing and fatigue wear are the predominant wear mechanisms of the composites.

Economical spherical GSD WC particles can be used to improve the wear resistance. The novel WC/18Ni300 composites are suitable for the application under the abrasive wear condition with low stress.

AA8090 aluminum alloy is used in industrial applications for weight reduction purposes. However, its usage is limited due to shortcomings such as low wear resistance. Hence, the purpose of this study is to improve the wear properties of the material. A particle strengthening mechanism was tried to improve the wear properties of materials.

AA8090 aluminum alloy composites were prepared by stir casting methods using AA8090, boron carbide (B₄C) and aluminum oxide (Al₂O₃) materials. Totally, four different types of composites were prepared, namely, AA/3Al, AA/1BC-2Al, AA/2BC-1Al and AA/3BC. Wear behavior and mechanical properties of the composites were analyzed by conducting wear test, microhardness test, tensile test and morphological analysis.

Results showed that the composite materials showed superior properties compared with AA8090 alloy due to the reinforcing effect of B₄C and Al₂O₃ particles. Further, the AA/3BC composite showed 12.9% and 10.8% enhancement in microhardness and tensile strength, respectively. Further, a minimum wear rate of 0.009 × 10^–3 mm³/m was observed for AA/3BC composite.

This study is original and would add new information to the literature. Further, it solves the problem of low wear resistance issues in AA8090 aluminum alloy materials.

Bangladesh is facing an alarming situation with the drinking water in its most areas, as groundwater used for drinking has been contaminated with naturally occurring inorganic arsenic. Many entrepreneurs along with the government are trying to cope up with this problem. SONO filter is one of them that is based on the social innovation concept. Social innovation is defined as innovative products/services motivated by the goal of meeting a social need, with the opportunity to create new social collaborations. This paper aims to examine the concepts of social innovation, which advocates enhancing values to society and the social benefit to all the stakeholders.

This is an exploratory study and presents the evolution, the development of the social business model and its implementation. Abul Hussam initiated the social business concept through SONO filter that is commercialized through the Manob Sakti Unnayan Kendro. The study has been conducted entirely on the basis of documentary information and data available in the public domain.

The findings show a hopeful contribution toward enhancing social benefits to society especially in arsenic-affected areas. SONO filter helps to mitigate the water-borne diseases and make people clean and safe, as well as healthy, by providing pure drinking water. Even by drinking pure water, people with arsenic-related diseases are getting better day by day through this social initiative.

Business based on social innovation is a new and really a good working concept. It has faced many hurdles in its journey to meet social objectives. Many researchers, entrepreneurs, non-profit organizations, national planners and society leaders will surely be benefited by its solution.

The purpose of this paper is to study the effect of blending time, SiC content and fill ratio on the homogeneity of iron‐silicon carbide powder mixture, blended in double‐cone blender; to evaluate density, microstructure and micro hardness of laser sintered iron and iron‐SiC specimens; and study the feasibility of building a complex iron‐SiC metal matrix composite (MMC) part by direct metal laser sintering (DMLS) process.

The morphology and particle size of iron and silicon carbide powders were evaluated. Nickel coating was carried out on silicon carbide particles. Blending of iron‐SiC powders were carried out in two phases in a double‐cone blending equipment. In the first phase, three tests were conducted with fill ratios (ratio of volume of conical blender to volume of powder mixture) of 1.68, 3.39, and 6.8 percent while iron‐SiC weight ratio was kept constant at 97:3. In the second phase, four tests were conducted with iron‐SiC weight ratios of 99:1, 98:2, 97:3, and 95:5 while keeping a constant fill ratio of 1.68 percent. In both the phases, blending was carried out for duration of 43 minutes. Homogeneity of the powder mixture was evaluated at different intervals of time by adopting sampling process. Sintering was carried out on iron and iron‐SiC powder mixture using DMLS machine at laser speed of 50, 75, 100, and 125 mm/s. Microstructure, density and micro hardness studies were carried out on the sintered specimens. A 3D model of a part with complex geometry was modeled using Unigraphics CAD/CAM software and prototype part was built by DMLS technology using the blended iron‐2 weight percent SiC powder.

A reduction in blending time was observed with increase in SiC content and decrease in fill ratio. Microstructure and micro hardness tests conducted on laser sintered iron‐silicon carbide specimens, reveal the homogeneity of blended powder. The density of the iron‐SiC composites sintered at a laser speed of 50 and 75 mm/s, decreased with increase in SiC content. Further, an increase in the micro hardness of iron‐SiC composites was observed with increase in SiC content and decrease in laser speed. Complex functional part was built by DMLS technology with out any supports.

The experiments were conducted with standard blending equipment in which the speed is limited to 48 revolutions per minute only.

Meager information is available on blending of powders for producing MMCs by laser sintering process. The work presented in this paper will be a guideline for researchers to carry out further work in blending of powders for producing MMCs by rapid prototyping process.

In this study, waste iron scale, which occurs in high amounts during steel production and contains high amounts of iron element, was used as a reinforcing material in the polypropylene (PP) matrix.

In the PP matrix, 33 micron-sized iron scale was added at 5%, 10%, 15% and 20% ratios. The composites were subjected to mechanical and dry sliding wear tests. The wear mechanisms occurring on the wear surfaces were determined by SEM supported by EDS. Tensile testing was performed using a tensile tester. Hardness tests were performed using a Shore-D hardness tester with ASTM-D-22 standards.

Composite reinforced with 5% iron scale showed the highest tensile strength. The addition of higher amounts of iron scale particles reduced the tensile strength of the composites compared to PP. Hardness increased from 58 to 64 Shore-D with the increase in scale content. The reinforcement of PP with iron scale increased the dry sliding wear resistance.

According to the authors’ knowledge, in the literature review, there was no study found on the effect of iron scale reinforcement on PP.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-08-2020-0316/

To improve the high-temperature wear properties of the SiCp/A359 composite, foamed iron-reinforced SiCp/A359 composite (A359–SiCp/Fe) is prepared. The purpose of this study is to investigate the tribological behavior and mechanism of the A359–SiCp/Fe composites at different temperatures (100–500 °C) and loads (7 N, 10 N and 12 N).

The A359–SiCp/Fe composite was fabricated by vacuum-assisted infiltration. The dry sliding tribological behaviors of A359–SiCp/Fe composite were investigated using the ball-on-disc-type tribometer. The worn surface and wear morphology of the longitudinal section were examined using field emission scanning electron microscopy and metallographic microscope.

The critical transition temperature for severe wear in A359–SiCp/Fe composite was 50–100 °C higher than in SiCp/A359 composite. Foamed iron prevents exfoliation cracks from penetrating deeper into the matrix. The friction coefficient stability of the A359–SiCp/Fe composite was higher than the unreinforced composite at elevated temperatures. With the increase in temperature, the friction-affected layer was severely worn, and the wear mechanism transferred from abrasion and delamination to oxidation and plastic flow, respectively.

The preparation procedure for aluminum matrix composites reinforced with foamed metal has been less reported, and the research on the tribological behavior and mechanism of A359–SiCp/Fe composite at various temperatures is insufficient. The foamed iron structure considerably enhances the wear properties of SiCp/A359 composite in elevated temperature conditions.

Presents development and characterisation of a new metal/polymer composite material for use in fused deposition modelling (FDM) rapid prototyping process with the aim of application to direct rapid tooling. The work represents a major development in reducing the cost and time in rapid tooling.

The material consists of iron particles in a nylon type matrix. The detailed formulation and characterisation of the thermal properties of the various combinations of the new composites are investigated experimentally. Results are compared with other metal/polymer composites used in rapid tooling.

The feedstock filaments of this composite have been produced and used successfully in the unmodified FDM system for direct rapid tooling of injection moulding inserts. Thermal properties are found to be acceptable for rapid tooling applications for injection moulding.

Introduces an entirely new metal based composite material for direct rapid tooling application using FDM RP system with desired thermal properties and characteristics. This will reduce the cost and time of manufacturing tooling inserts and dies for injection moulding.

This paper aims to produce iron ore tailings reinforced polypropylene composites (ITR-PPCs) from conventional compo-casting (CC) and a proposed compo-indirect squeeze casting (C-ISC) processes. It intends to quantify the compressive behaviour of ITR-PPC with respect to production process, iron ore tailings volume and particle size inclusion in polypropylene (PP) through controlled material and compressive testing. The study aims to provide useful information on possibility of the use of ITR-PP for compressive applications which will culminate to judicious use of iron ore tailings that is been piled up as waste material at the iron ore beneficiation sites.

ITR-PPC compression specimens were produced using C-ISC and CC processes. Prior to production, the iron ore tailings was dried at room temperature according to ASTM 618, ASTM 171 and ASTM E 41. The different particle sizes were generated using standard laboratory sieves. Uniaxial compressive test procedure according to ASTM D 695 was carried out on ITR-PPC compression specimens with length/diameter ratio equal to 2.0 under standard laboratory atmosphere on an Instrom 3,369 machine.

It was discovered that pure PP produced using the C-ISC process exhibited better compressive strength and Young’s modulus of about 12 and 4.5 per cent, respectively, while a reduction of 9.2 per cent in yield strength was recorded. ITR-PPCs with 150-μm fillers produced from C-ISC process have lower yield stress, compressive strength and Young’s modulus at volume contents above 10 per cent. It also exhibited lower strain at fracture at volume content above 15 per cent, while composites filled with 212- and 300-μm particle size iron ore tailings using the C-ISC process had better strain at fracture.

The present work cannot ascertain the compressive behaviour of ITR-PPC produced from other production processes, hence the need for further work in this area.

The paper provides an avenue to address the pollutant effect of iron ore tailings by putting it to judicious use through addition as fillers in plastics. It also removes the need for expensive and repeated experimentation to determine the compressive behaviour of ITR-PPCs.

This paper has brought to fore the need to study iron ore tailings as filler in plastics and other material matrices.

The purpose of this study is to investigate the tribological properties of society of automotive engineers (SAE) 430B bronze-graphite composite, supplied in the form of machined and graphite embedded, used in sheet forming industry.

Pin-on-disc wear tests were performed under a constant normal load of 15 N and a sliding velocity of 60 mm/s. Due to the extended usage of Fe-based alloys in forming dies, pin materials were selected as cold work tool steel, gray and ductile irons. The weight losses of the disc (SAE 430B bronze-graphite composite) and the pins (Fe-based alloys) were measured separately under various sliding distances (5,000, 10,000 and 15,000 m). The average friction coefficients and wear tracks were obtained.

It is concluded that dry sliding behavior of SAE 430B bronze-graphite composite is the worst when operated with GGG-70 ductile iron due to its highest abrasive effect. The high hardness and nodular shape of graphite increased the abrasiveness of ductile iron. The improvement in wear resistance reached up to maximum 90 per cent and the degradation in friction coefficient was about 50 per cent by embedding graphite solids in bronze disc at dry sliding conditions.

Although the machined and graphite embedded bronze composites are indispensable parts of forming dies, there is no scientific knowledge on their dry sliding behavior.