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The fused filament fabrication (FFF) which is also known as freeform filament fabrication is one of the additive manufacturing techniques used for the fabrication of functional and nonfunctional prototypes. The previous studies have suggested that FFF process parameters have significant impact over the mechanical, thermal, surface, morphological and tribilogical properties of the 3D printed parts. The present study deals with the investigation for process parameters of FFF. In this study, three different process parameters namely; infill percentage, bed temperature and outer perimeter have been varied for the FFF process. The 3D printed nylon 6 prototypes (As per ASTM 638 type IV) were tested by universal tensile tester for investigation of ultimate tensile strength. The results of the study have suggested that at 100% infill percentage, 60% and 6 outer perimeters the ultimate tensile strength can be maximized.

The effect of numerous process variables has been explored for surface roughness and material removal rate during the magnetic abrasive finishing process. A hybrid approach was used in which the Taguchi technique is used in conjunction with grey relational analysis to reach the optimum combination of input variables. The L16 orthogonal array design was used to get a different combination of parameters. It was found that spindle speed of 200 rpm, the quantity of magnetic abrasives of 5 mg, mesh number of 270, and machining time 60 min caused minimum surface roughness of 0.066 µm during magnetic abrasive finishing of the brass plate. The percentage contribution of input parameters has been reported. Subsequently, the optimum results were obtained using multi-objective optimization techniques of grey relational analysis, and results were also validated using experimentation.

Modern machining trends are continuously expanding nowadays, especially the various vibrational-based machining processes (VBM) exemplify as ultrasonic machining, ultrasonic vibration assistant machining, and rotary ultrasonic machining (RUM) processes. Therefore, this review study has been focused on these three machining techniques with an explanation of their parameters, physics, mechanism, and application. Also reported that the rotary ultrasonic machining and other vibration-assisted machining processes are used explicitly to machine hard, and brittle material exemplifies as ceramic, glass, bone, titanium alloy, silicon carbide, etc. There is a critical need for developing the models of process performances such as cutting force, tool wear rate, surface roughness, material removal rate, etc. Therefore, improvement in the USM, rotary ultrasonic machining, and UVA technique should be considered and explore the work up to an optimum machining limit.

Drilled hole quality is a significant parameter for successful orthopedic surgery. The present investigation is an effort to reduce the delamination produced drilling with state-of-the-art hybrid drilling i.e. ultrasonically-assisted drilling. A comparative analysis has carried out as per experimental design to assess the ultrasonic drilling with conventional drilling. The novelty of the work is the use of coordinate measuring machine (CMM) for characterization of the delamination during bone drilling. The results revealed that ultrasonically-assisted drilling caused lesser delamination than conventional drilling. The maximum percentage delamination during conventional drilling was found to be 9.153% and 8.541% during ultrasonically-assisted drilling.

PurposeIn present research work, the effects of rotational speed, feed rate and vibration amplitude have been investigated during novel method of ultrasonic-assisted bone grinding. During dissection of tumors, firstly a bone flap is removed near the target region to create passage for grinding burr. During abrasion, heat is produced, which sometimes increases the temperature to unsafe levels. So, efforts have been made to limit the temperature below the threshold levels of osteonecrosis during bone grinding.Design/methodology/approachThe temperature produced during osteotomy has been measured using infrared thermography camera during the implementation of L18 Taguchi orthogonal array design. Subsequently, main effect plots and contour plots have been presented to analyze and visualize the effect of grinding parameters on temperature rise during bone grinding. Furthermore, the process parameters have been optimized for optimum results for response characteristics using Taguchi SN ratio-based optimization methodology. For multiobjective optimization, the process parameters are further optimized using grey relational analysis.FindingsIt is revealed that all three process parameters substantially affect the response characteristics. The proposed optimization methodology is successfully applied on the experimental findings and the optimum results for change in temperature are found to be rotational speed = 3,000 rpm, feed rate = 20 mm/min, amplitude = 10 µm and for standard deviation are 5,000 rpm, 60 mm/min, 10 µm.Research limitations/implicationsThe present research findings cannot be generalized, and researchers are encouraged to further investigate the proposed rotary ultrasonic-assisted bone grinding at higher rotational speed up to 60k rpm on the skull bone.Originality/valueThe research on osteotomy is still at its initial phase, and continuous research is carried out for making patients’ life comfortable. In this direction, the authors have proposed a novel osteotomy method to limit the temperature below the threshold limit of osteonecrosis. The outcomes of the present study will be beneficial for the neurosurgeons working in this field.

Components operating in fluid handling systems most frequently experience cavitation erosion. The coatings/claddings fabricated by microwave irradiation method can remarkably improve cavitation erosion. In the present work, WC reinforced NiCrSiC based metal matrix composite clads with varying weight percentage of WC particles were developed on SS 316 steel using microwave heating method. The metallurgical and microstructural study of composite clads were analyzed using SEM/EDS, XRD and porosity, microhardness was also investigated. Cavitation erosion behavior of the claddings were evaluated using vibratory cavitation erosion tester. The failure mechanism due to cavitation erosion was explored using SEM study. The relationship of cavitation erosion behavior with variation in weight percentage (10%, 20%, and 30%) of reinforced particles in the composite clad was also explored. It has been observed that with an increase in the weight percentage of WC particles, the cavitation erosion rates decreased drastically initially (37.9%) and, but later significant change was not observed (4.89%, 2.44%). Eroded surface study revealed that with increase in the weight percentage of WC reinforcement the mode of damage changes from ductile to brittle. Further it was studied that the pits, crater, micro-cracks, and plastic deformation were the primary wear mechanisms.

Fiber-reinforced polymer (FRP) matrix materials are quickly being investigated for application in concrete construction repair, reinforcement, and refurbishment. The technology has progressed to the point that its future acceptance is mainly reliant on the availability of established design guidelines based on recognized performance criteria, as well as the cost competitiveness of these technologies in contrast to conventional rehabilitation methods. The goal of this study is to evaluate the different functional grades of adhesives throughout bond length for bonded socket joints of laminated FRP composite pipes. Damage development resistance is high with a functionally graded FRP composite socket joint, as shown. To extend the service life of the structure, the joint designer should use an FRP composite socket joint with a functionally graded adhesive (FGA).

The present research investigations are based on the simultaneous finishing of ring-shaped cylindrical aluminium alloy workpiece having utility in multitude areas such as medical, defence, automobile, aerospace, and manufacturing ventures. To accomplish this objective, a novel in-situ fixture is designed and fabricated for simultaneous finishing of the inner, outer, and side surface. The silicone polymer-based abrasive media is prepared and is tested on the workpiece. The effect of different machining parameters is investigated in terms of response characteristics such as a change in surface roughness and percentage improvement. The surface roughness before and after abrasive flow machining has been analyzed under a microscope to reveal surface endowment. It has been pragmatically observed that abrasive mesh size, the concentration of abrasives, and a number of passes has a significant effect on change in surface roughness. The maximum percentage improvement in the surface roughness found to be 35.71 %, 37.89 %. and 27.16 % on the inner, outer, and side surface respectively. The surface micrographs after finishing showed the direction of abrasives, media flow direction, the direction of single point cutting tool, and material removal via ploughing effect owing to the high indentation of abrasive grits.

This review has been carried out to present a comprehensive review of all the neurosurgical bone grinding investigations pertinent to temperature rise during osteotomy. The experimental methods and results obtained by past researchers are elucidated along with conclusions and methodology used for achieving results. This systematic review identifies thermo-mechanical aspects and different temperature measurement techniques. The detailed discussion has been carried for temperature measurement during surgical osteotomy along with the effect of thermogenesis and thermal necrosis on soft and hard tissues. The review suggests that there is no general agreement exists for thermal necrosis threshold temperature among investigators. However, the temperature of 47 °C for 1 min has been considered as the temperature to cause thermal necrosis.

The review study considers the three-dimensional printing for anatomical simulations and their potential surgical applications. Three-dimensional (3D) printing has entirely transform the current era with its state-of-art usefulness and applications. The functional usability of three-dimensional printed models has been mentioned for orthopaedic, neurosurgery, heart valve surgery, and malignant tissues. Surgical planning of congenital anomalies has also pondered. By 3D printed models, surgical anatomical teaching methods have been explained. The key significance of 3D printed models during treatment of benign and cancerous tumors have been pointed with the conception of bone grinding. In final section, the complications and merits of 3D printed models in surgery have been postulated along with the ethical concerns associated with 3D printed models.

Electrical discharge machining (EDM) has recently been shown to be one of the most successful unconventional machining methods for meeting the requirements of today’s manufacturing sector by producing complicated curved geometries in a broad variety of contemporary engineering materials. The machining efficiency of an EDM process during hexagonal hole formation on pearlitic Spheroidal Graphite (SG) iron 450/12 grade material was examined in this study utilizing peak current (I), pulse-on time (Ton), and inter-electrode gap (IEG) as input parameters. The responses, on the other hand, were the material removal rate (MRR) and overcut. During the experimental trials, the peak current ranged from 32 to 44 A, the pulse-on duration ranged from 30–120 s, and the inter-electrode gap ranged from 0.011 to 0.014 mm. Grey relational analysis (GRA) was interwoven with a fuzzy logic method to optimize the multi-objective technique that was explored in this EDM process. The effect of changing EDM process parameter values on responses was further investigated and statistically analyzed. Additionally, a response graph and response table were produced to determine the best parametric setting based on the calculated grey-fuzzy reasoning grade (GFRG). Furthermore, predictor regression models for response characteristics and GFRG were constructed, and a confirmation test was performed using randomly chosen input parameters to validate the generated models.

Bone grinding is a craniotomy procedure which is used to remove a bone flap from the skull to expose and create an access for the dissection of tumors. In this study, a computer-controlled neurosurgical bone grinding has been used to explore the effect of various neurosurgical bone grinding parameters, such as cutting forces, torque, grinding force ratio, and temperature generated during bone grinding have been investigated. Bone samples after grinding have been assessed for morphological analysis. Based on the outcomes, a multi-attribute decision-making methodology based on grey relational analysis has been adopted. Regression models have been developed and then validated to ensure the adequacy of the developed models. Subsequently, a comparative analysis of experimental and predicted results have been presented. It is revealed that grinding forces and torque decreased with the escalation of rotational speed from 35,000 revolutions per minute (rpm) to 55,000[Formula: see text]rpm. The optimum combination of process parameters found as rotational speed of 55,000[Formula: see text]rpm, feed rate of 20[Formula: see text]mm/min, and depth of cut of 0.50[Formula: see text]mm.

This chapter provides a comprehensive insight into 3D printing materials, techniques, and potential applications. Materials such as photopolymers, thermoplastics, metals, edible materials, plastics, and plaster have been discussed. Furthermore, techniques such as fused deposition modeling, stereolithography, selective laser sintering, and powder inkjet 3D printing have been explained with schematic illustrations. Subsequently, 4D printing has been explained along with the material’s requirements and considerations. The use of 3D printing in biomedical engineering has been briefly explained. Surgical and dental implants, disease modeling, pharmaceuticals, and organ printing, either in part or full, have been lightened. In the last section, the experimental outcomes of the 3D printed scaffolds have been explained along with their synthesis process, degradation behavior, and bioactivity.

The present work explores the potential of magneto-rheological fluid assisted abrasive finishing (MRF-AF) for obtaining precise surface topography of an in-house developed &beta, phase Ti-Nb-Ta-Zr (TNTZ) alloy for orthopedic applications. Investigations have been made to study the influence of the concentration of carbonyl iron particles (CIP), rotational speed (Nt), and working gap (Gp) in response to material removal (MR) and surface roughness (Ra) of the finished sample using a design of experimental technique. Further, the corrosion performance of the finished samples has also been analyzed through simulated body fluid (SBF) testing. It has been found that the selected input process parameters significantly influenced the observed MR and Ra values at 95% confidence level. Apart from this, it has been found that Gp and Nt exhibited the maximum contribution in the optimized values of the MR and Ra, respectively. Further, the corrosion analysis of the finished samples specified that the resistance against corrosion is a direct function of the surface finish. The morphological analysis of the corroded morphologies indicated that the rough sites of the implant surface have provided the nuclei for corrosion mechanics that ultimately resulted in the shredding of the appetite layer. Overall results highlighted that the MRF-AF is a potential technique for obtaining nano-scale finishing of the high-strength &beta, phase Ti-Nb-Ta-Zr alloy.

This chapter focuses on the main parameters, physics, and applications behind the manufacturing of microcomponents. It includes topics of process physics, specific cutting energy, ductile mode machining, edges chipping, cutting fluid, and surface finishing of the microcomponents. According to Rajput, micromachining is a concern with miniaturization of shape and size of the product by conventional as well as nonconventional machining techniques. Definitely, the miniaturization of the products leads to a large extent of applications. In spite of this, miniaturization is also creating some negative effects on the cost of manufacturing, metrological instrumentation, working stability, and so on. Micromachining techniques have sustained many characteristics related to the conventional machining. Once the ratio between the workpiece size and the tool dimension (width or length) became diminished, the miniaturization of the size may lead to affect the all the parameters such as the depth of cut with respect to the tool edge radius.

In today’s era of hybrid machining, there is a continuous demand of highly precise dimensional products. The hybrid machining processes are gaining interest for the researchers to have more efficient and productive part in the segments of electronics, automotive, and aerospace industries where high accuracy and surface quality are of great concern. Different hybrid machining processes are being used for different purposes to increase finishing till micro- and nano-levels. From the past years, conventional finishing processes such as grinding and honing are generally used to finish the surface of these components. But still more machining efficiency and cost reduction is still under play. These problems can be resolved using magnetorheological (MR) finishing processes. These processes use MR polishing fluids which behave like semisolid fluid under the magnetic field with controlled finishing forces. This chapter emphasizes on the capability of various magnetically assisted finishing processes for various internal and external surfaces with their mechanism of material removal. The MR abrasive flow finishing (MRAFF) process is investigated for the internal cylindrical finishing of non-ferromagnetic specimens. Also, rotational-MRAFF (R-MRAFF) process is slightly modified to increase the process performance and to raise the shearing tendency of the abrasive particles for enhancing the surface roughness. Further, a novel ball-end MR finishing (BEMRF) process is developed for finishing the 3-D surfaces through BEMRF tool. Lastly, magnetorheological honing (MRH) process has been discussed that focused on finishing the internal surface of ferromagnetic specimens. KeywordsHybrid machining; Magnetorheological finishing processes; Ferrous material; Magnetorheological honing process.