Engineering and Technology Journal

Appropriate cranial implants are essential due to a worldwide population that is aging and the rising incidence of trauma. One key element affecting cranial implants' performance is their biomechanical behavior in human skull bones. This paper describes a high-quality cranial implant design approach for the defective skull based on computed tomography CT scan images and the biomechanical performance analysis of rehabilitation human skull bones. The valuable contribution of this work is the effective utilization of finite element analysis FEA to contrast the material behaviors of Polymethylmethacrylate PMMA cranial implants and autologous skull bone during rehabilitation as exposed to external trauma. The external loads applied in the implant's center are attached to a damaged cranium (300, 600, and 1000 N). The findings indicated that the equivalent stresses of PMMA are close to the skull bone. Minimum and maximum Von Mises stresses are (13 and 47 MPa) when employing a PMMA implant material and (12 and 41 MPa) when utilizing autologous skull bone at the lowest and highest level of applied force (300 and 1000 N), respectively. In terms of deformation distribution (0.02 and 0.03 mm) at applying 300 N, approximately six times the weight of a human head when the reconstruction is performed by skull bone and PMMA, respectively. So, this study will offer an insightful look at the neurocranial protection of PMMA implants that provide the coupling of skull bone-PMMA cranial implant, which guarantees adequate protection for the internal structures of the restored area similar to the autologous skull bone.

Nanotechnology in electrode manufacturing is a new technique to enhance the machinability of materials that are difficult to machine using electrical discharge machining (EDM). Since the wear of electrodes in the EDM process usually has a high effect on the process performance, thus it is important to conduct a study to reduce the tool wear rate (TWR) and increase the Material removal rate (MRR). This study aims to improve the operation performance of nanomaterial graphene in the electrode industry. In this experimental work, single-layer nanographene with a concentration of (2%wt) was mixed into a copper matrix using the stir-casting method for machining AISI 1005 Carbon Steel. The parameters selected are discharge current Ip (20, 30, and 40 A), pulse on time Ton (100, 200, and 300 μs), and pulse off time Toff (100, 150, and 200 μs). All the experimental runs were conducted using Design Expert 13 software at three levels and ANOVA for the statistical study. The results of this study manifested that the EDM performance was significantly enhanced by utilizing the powder of nanographene and enhancement through the performance measures of TWR and MRR improved by 15.10% and 29.67%, respectively, and enhanced the economic efficiency of this technology through the improved mechanical and electrical properties. Finally, scanning electron microscopy (SEM) was used to examine the effect of nanographene on the machined surface quality. The surface obtained from the copper electrode elucidated more surface flaws compared to the electrode mixed with nanographene powder.

Most research on single-point incremental forming (SPIF) has focused on aluminum sheets of various thicknesses and titanium and steel with moderate mechanical resistance and low thicknesses. However, brass alloys, which exhibit moderate resistance comparable to certain aluminum alloys, have yet to receive much attention from researchers. Consequently, the formability of brass alloys requires a more thorough investigation. This study examines two ductile materials: Aluminum 1100 and Brass CuZn37. Both materials were formed under identical conditions into a hyperbolic truncated pyramid with varying wall angles ranging from 20° to 80° using the SPIF process, with dimensions of 150 mm × 150 mm and a thickness of 0.8 mm. A comparison was made based on fracture depth, maximum wall angle, and minimum thickness before fracture to evaluate the formability of brass alloys in relation to aluminum alloys. The results indicate that while Aluminum 1100 exhibits higher formability than Brass CuZn37, the differences in formability between the two materials are relatively small. The fracture depth, maximum wall angle, and minimum thickness before fracture were 37.1 mm, 80.21°, and 0.24 mm for Aluminum 1100, compared to 34.4 mm, 76.81°, and 0.33 mm for Brass CuZn37. Notably, the effect of process parameters on the formability of Brass CuZn37 was significantly greater than their effect on Aluminum 1100.

Surface roughness is a critical parameter that profoundly influences the functionality and performance of materials and components across various industries. Additionally, estimating the ideal machining parameter circumstances is the best way to minimize costs and get the item's surface quality. This research investigated four factors- depth of cut, spindle speed, feed, and nose radius- for the turning of aluminum alloy AA2024 to estimate the surface roughness. The study's experimental efforts were done by utilizing a manual turning machine, and the experiment setup used the Taguchi method of L18 array orthogonal (OA). The Taguchi approach is employed to optimize the selection of tools. The average surface roughness (Ra) measurements were converted to signal-to-noise (S/N) ratios and analyzed statistically using the analysis of variance (ANOVA) method. The results illustrated that nose radius, feed, speed, and depth of cut that produced the best results were 0.8, 0.066 mm/min, 1100 rpm, and 0.9 mm, respectively. The feed rate contributed the most with 54.51%, while the nose radius had the smallest impact with 0.84% of the percentage contribution. A2/B3/C1/D2 is the most efficient arrangement for lathe parameters. Among the selected components, only the feed rate showed a significant P-value of 0.006. Surface roughness offers numerous benefits for AA2024, an aluminum alloy widely utilized in aerospace applications. Enhanced surface roughness fosters better adhesion of coatings and adhesives and is crucial for strong bonds in aircraft components.