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This study aims to highlights the mechanical, thermal and melting behavior compatibility of aluminum (Al)-reinforced polyamide (PA) 6/acrylonitrile butadiene styrene (ABS)-based functional prototypes prepared using fused deposition modeling (FDM) from the friction welding point of view. Previous studies have highlighted the use of metallic/non-metallic fillers in polymer matrix for preparations of mechanically improved FDM feedstock filaments and functional prototypes. But hitherto, very less has been reported on fabrication of functional prototypes which fulfill the compatibility of two polymers for joining/welding-based applications. The compatibility of two dissimilar polymers enables the friction welding for maintenance applications.

The twin screw extrusion process has been used for mechanical mixing of metallic reinforcement in polymer matrix, and final blend of reinforced polymers in the form of extruded feed stock filament has been used on FDM for printing of functional prototypes (for friction welding). The methodology involves melt flow index (MFI) investigations, differential scanning calorimetry (DSC) investigations for thermal properties, tensile and hardness testing for mechanical properties and photo micrographic investigations for metallurgical properties on extruded samples.

It was observed that the reinforced ABS and PA6 polymers have better compatibility in the terms of similar melt flow, thermal properties and can lead to the better joint efficiency with friction welding.

In the present work composite feed stock filament composed of ABS and PA6 with reinforcement of Al powder has been successfully developed for preparation of functional prototype in friction welding applications.

The present research was envisaged with an aim to optimize the system and the product responses for the development of tomato pomace-incorporated corn-based extrudates employing central composite rotatable design and determine its proximate, lycopene, consumer acceptability and storage studies.

Lycopene-rich extrudates were developed from corn flour blended with different levels of tomato pomace. The independent extrusion variables, namely, feed composition (95:5 to 75:25), feed moisture (12–20%), screw speed (200–600 rpm) and barrel temperature (125–185 °C), were studied to determine their influence on dependent variables, namely, specific mechanical energy, hardness, water solubility index, lateral expansion, water absorption index, bulk density and color.

All of the quality parameters were significantly (p < 0.05) influenced by independent variables. The regression models obtained for all the responses showed high coefficients of determination (R2 = 0.85–0.95). The optimum conditions for the development of tomato pomace-incorporated corn-based extrudates were feed composition (90:10), feed moisture (14%), screw speed (300 rpm) and barrel temperature (170 °C). The moisture, fat and carbohydrate contents of the extrudates were significantly reduced, whereas protein, ash and fiber were significantly (p < 0.05) enhanced after the incorporation of tomato pomace. Aluminum laminates were found to be the suitable packaging materials for extrudates for a period of 120 days in comparison to high-density polyethylene packages.

As far as the authors could possibly know, scanty literature exists wherein the tomato pomace has been utilized for the development of lycopene-rich corn-based extruded snacks. Such extrudates with significantly higher fiber and lycopene contents than corn flour will serve as a suitable alternative for the development of shelf-stable ready-to-eat extruded snacks.

This study aims to explore a technique of metal additive manufacturing (MAM) for producing parts in aluminium. The proposed technique mimics the process of metal injection moulding but with the tools meant for fused freeform fabrication machines.

The work focusses on the preparation of novel feedstock by mixing the aluminium powder with binders made from different compositions of high-density polyethylene, paraffin wax, petroleum jelly and stearic acid. Further, a novel experimental setup with a paste extruder was designed to print the test samples. A sintering cycle was developed in-house along with a thermal debinding procedure. An experimental campaign was also carried with the proposed technique to establish a proof-of-concept. Produced samples were tested for part density, hardness, compressive strength and tensile strength.

The results indicate geometrical accuracy was an issue owing to the presence of petroleum jelly in the binder-powder mixture. Therefore, machining as a post-processing operation seems to be unavoidable. The study also elucidates that the printed specimen may require further heat treatment to replace wrought alloys. However, the sintered parts show hardness and compressive strength similar to that of wrought aluminium alloy.

The novelty of the work is to develop the cost effective and scalable powder extrusion-based MAM process for printing the aluminium parts.

Three-dimensional printing of concrete (3DPC) has a potential for the rapid industrialization of the housing sector, with benefits of reduced construction time due to no formwork requirement, ease of construction of complex geometries, potential high construction quality and reduced waste. Required materials adaption for 3DPC is within reach, as concrete materials technology has reached the point where performance-based specification is possible by specialists. This paper aims to present an overview of the current status of 3DPC for construction, including existing printing methods and material properties required for robustness of 3DPC structures or structural elements.

This paper has presented an overview of three categories of 3DPC systems, namely, gantry, robotic and crane systems. Material compositions as well as fresh and hardened properties of mixes currently used for 3DPC have been elaborated.

This paper presents an overview of the state of the art of 3DPC systems and materials. Research needs, including reinforcement in the form of bars or fibres in the 3D printable cement-based materials, are also addressed.

The critical analysis of the 3D concrete printing system and materials described in this review paper is original.

The purpose of this paper is to study the functionality of additively manufactured (AM) parts, mainly depending on their dimensional accuracy and surface finish. However, the products manufactured using AM usually suffer from defects like roughness or uneven surfaces. This paper discusses the various surface quality improvement techniques, including how to reduce surface defects, surface roughness and dimensional accuracy of AM parts.

There are many different types of popular AM methods. Unfortunately, these AM methods are susceptible to different kinds of surface defects in the product. As a result, pre- and postprocessing efforts and control of various AM process parameters are needed to improve the surface quality and reduce surface roughness.

In this paper, the various surface quality improvement methods are categorized based on the type of materials, working principles of AM and types of finishing processes. They have been divided into chemical, thermal, mechanical and hybrid-based categories.

The review has evaluated the possibility of various surface finishing methods for enhancing the surface quality of AM parts. It has also discussed the research perspective of these methods for surface finishing of AM parts at micro- to nanolevel surface roughness and better dimensional accuracy.

This paper represents a comprehensive review of surface quality improvement methods for both metals and polymer-based AM parts.

In recent years, additive manufacturing (AM) technology has been acknowledged as an efficient method for producing geometrical complex objects with a wide range of applications. However, dimensional inaccuracies and presence of defects hinder the broad adaption of AM procedures. These factors arouse concerns regarding the quality of the products produced with AM and the utilization of quality control (QC) techniques constitutes a must to further support this emerging technology. This paper aims to assist researchers to obtain a clear sight of what are the trends and what has been inspected so far concerning non-destructive testing (NDT) QC methods in AM.

In this paper, a survey on research advances on non-destructive QC procedures used in AM technology has been conducted. The paper is organized as follows: Section 2 discusses the existing NDT methods applied for the examination of the feedstock material, i.e. incoming quality control (IQC). Section 3 outlines the inspection methods for in situ QC, while Section 4 presents the methods of NDT applied after the manufacturing process i.e. outgoing QC methods. In Section 5, statistical QC methods used in AM technologies are documented. Future trends and challenges are included in Section 6 and conclusions are drawn in Section 7.

The primary scope of the study is to present the available and reliable NDT methods applied in every AM technology and all stages of the process. Most of the developed techniques so far are concentrated mainly in the inspection of the manufactured part during and post the AM process, compared to prior to the procedure. Moreover, material extrusion, direct energy deposition and powder bed processes are the focal points of the research in NDT methods applied in AM.

This literature review paper is the first to collect the latest and the most compatible techniques to evaluate the quality of parts produced by the main AM processes prior, during and after the manufacturing procedure.

The purpose of this paper is to review the various pre-processing and post-processing approaches used to ameliorate the surface characteristics of fused deposition modelling (FDM)-based acrylonitrile butadiene styrene (ABS) prototypes. FDM being simple and versatile additive manufacturing technique has a calibre to comply with present need of tailor-made and cost-effective products with low cycle time. But the poor surface finish and dimensional accuracy are the primary hurdles ahead the implementation of FDM for rapid casting and tooling applications.

The consequences and scope of FDM pre-processing and post-processing parameters have been studied independently. The comprehensive study includes dominance, limitations, validity and reach of various techniques embraced to improve surface characteristics of ABS parts. The replicas of hip implant are fabricated by maintaining the optimum pre-processing parameters as reviewed, and a case study has been executed to evaluate the capability of vapour smoothing process to enhance surface finish.

The pre-processing techniques are quite deficient when different geometries are required to be manufactured within limited time and required range of surface finish and accuracy. The post-processing techniques of surface finishing, being effective disturbs the dimensional stability and mechanical strength of parts thus incapacitates them for specific applications. The major challenge for FDM is the development of precise, automatic and controlled mass finishing techniques with low cost and time.

The research assessed the feasibility of vapour smoothing technique for surface finishing which can make consistent castings of customized implants at low cost and shorter lead times.

The extensive research regarding surface finish and dimensional accuracy of FDM parts has been collected, and inferences made by study have been used to fabricate replicas to further examine advanced finishing technique of vapour smoothing.

The purpose of this paper is to present three-dimensional (3D) printing of structures with a new method called selective laser baking (SLB) of Poly Dimethyl Siloxane (PDMS).

A 3D model is designed on the computer. PDMS Base is mixed with its hardener and poured into a container. Before it is hardened which normally occures after several hours, a CO₂ laser selectively exposes different areas on the surface of the PDMS mixture according to the pattern of a slice of a 3D model designed on the computer. Because of the thermal effect of the CO2 laser, once exposed, PDMS heats up and hardens, producing a cured layer of PDMS which is attached to a base. The base with the cured layer is lowered in the container for a short distance and a layer of new uncured PDMS is spread over the previous layer. The laser exposes new areas again and hardens them. This process is repeated until the whole structure is fabricated.

The parameters involved in the baking process are investigated and the relation between temperature, mixing portion and laser irradiance on the curing time and layer thickness are investigated.

This fabrication technique is a unique fabrication method that helps to 3D print with two base polymers which their polymerization can be boosted by heat. This 3D printing method has not been presented earlier.

The purpose of this paper is to present a report on the implementation of a quality cost program in a continuous‐process manufacturing company, with particular emphasis on the unearthing of hidden quality costs, as well as gaining a closer understanding of the resistance against implementation.

Using an action research approach, the researchers participated – directly and indirectly – in the implementation of quality costing at the case company. The research process comprises iterative cycles of gathering data through documentary reviews, observations of company operations, discussions with operatives, analyzing data, undertaking actions and evaluating results. Following Sandoval‐Chavez and Beruvides, the poor quality cost analysis includes an additional category to the conventional prevention‐appraisal‐failure model to reflect the cost of lost opportunities.

The study unearthed a significant portion of hidden quality costs which may be termed an “opportunity loss”. The findings indicate that the company's total quality costs actually far exceed its current profit margin, and that the company could improve its competitive position if it focused on the elimination of these quality costs.

This paper focuses on uncovering hidden quality costs. However, the measuring of quality costs only serves to identify opportunities for improvement. It is follow‐up corrective actions that will lead to organizational effectiveness. The research findings support the contention that tracking of poor quality costs is an important step in the quality management process.

This paper presents a proactive way of tracking hidden quality costs.

This paper aims to review the industrial and biomedical applications of state-of-the-art fused deposition modelling (FDM)-assisted investment casting (FDMAIC). Brief literature survey of methodologies, ideas, techniques and approaches used by various researchers is highlighted and use of hybrid feedstock filament-based pattern to produce metal matrix composite is duly discussed.

Pattern replica required for investment casting (IC) of biomedical implant, machine parts, dentistry and other industrial components can be directly produced by using FDM process is presented. Relevant studies and examples explaining the suitability of FDMAIC for various applications are also presented.

Researches to optimize the conventional IC with FDM solutions and develop new hybrid feedstock filament of FDM done by researchers worldwide are also discussed. The review highlights the benefit of FDMAIC to surgeons, engineers and manufacturing organizations.

The research related to this survey is limited to the suitability and applicability of FDMAIC.

This review presents the information regarding potential IC application, which facilitates the society, engineers and manufacturing organizations by providing variety of components for assisting FDM. The information reported in this paper will serve doctors, researchers, organizations and academicians to explore the new options in the field of FDMAIC.