Iraqi journal of mechanical and material engineering

This study describes an influence of zirconia addition on some porcelain properties, particularly mechanical properties such as hardness and strength, depending on results of some previous researches which describe the methods of porcelain strengthening and toughening due to use the porcelain in many applications in daily life, such as dental porcelain, electrical porcelain and sanitary ware from porcelain. Porcelain has very important properties which make it a suitable material to other promised applications. For this reason, it must be defined the last information to which the recent researches reached to benefit from those methods in an improving of the porcelain properties to use it in suitable applications. This study showed that it can be significantly benefited from the zirconia addition to porcelain in an improving of many properties for it.

A well-recognized technique for producing compressive residual stresses beneath the surface of metal is laser shock peening (LSP), which increases the material's durability to wear and corrosion and improves fatigue life. Comparing LSP to traditional mechanical shot peening, it provides a more dependable surface treatment and may minimize microstructural damage. This surface treatment method involves directing a powerful laser pulsation at the superficial in extremely tiny pauses. Due to the capabilities available in this alloy AA7075-T651. As an important formability, automation and corrosion resistance, it will certainly have very large uses, including aircraft structures, and to improve the properties of this alloy, this technical method was used. The treated surface of Al-alloy 7075-T651 was made harder and more desirable during this investigation by employing a novel approach that involved the use of pure water and hydrofluoric acid (HF) as confinement layers. It was found that applying Hydrofluoric Acid (HF) significantly extended the pieces' fatigue life after laser peening as compared to unpeened specimens and pure water. Additionally, the Vickers hardness test results revealed that LSP with the utilized two confinement liquid, as well as unpeened samples, exhibited hardness values of 153HV30, 121HV30, and 94HV30, respectively, demonstrating a substantial improvement in hardness properties.
The test results show that, when compared to unpeened samples, every site of interest deal with the in-elevation cycle fatigue zone by LSP with two confinement liquid achieved a considerable improvement in life and strength, arriving at 88%and 72%, respectively. The SEM images showed that the untreated specimens had surface crack initiation location. The peened specimens showed two regions, the hardened and non-hardened region. The depth of the hardened area of the peened specimens was measured. The results of the experiment support the assumption that peening increases the fatigue life of alloys. The hardened surface and compressive residual stress field created by peening make it harder for cracks to initiate and propagate.

Design and analysis of optimisation protocols used for performance enhancement of machining based components manufacturing is currently an active area of machining science. This experimental investigation research deals with determining and optimising the effects of three input parameter metrics on the performance realisation of good surface quality output and energy consumption during the dry machining process of EN 24 steel material by turning on the CNC lathe. The input parameter metrics considered were cutting speed, depth of cut and feed rate. The study, employed Taguchi full factorial design approach in planning the experimental process and estimate the effects of the input metrics on the response; three phase digital energy meter to capture electrical power consumption data online; offline recorded surface roughness data and used Minitab 18 statistical software analysis of variance to assess the influence of cutting parameters on the response parameters, and the Signal to noise ratio main effects plot as the optimisation tool for the various response parameters. The paper aimed to determine the appropriate cutting parameter settings required on the lathe machine in order to produce EN 24 components of better surface quality at minimum energy expenditure. The experimental data analysis results established the optimum operating conditions at varied cutting parameter settings with respect to the different response parameters and the results were presented for the surface roughness, material removal rate and specific cutting energy use.

The present study offers a thorough examination of the utilization of vibration techniques in the evaluation of bone healing in the domain of orthopedics and rehabilitation. In addition to providing critical insights into the mechanical properties of healing bones and their influence on treatment choices, the review includes an investigation of objective, non-invasive techniques for tracking the advancement of bone healing. The study also explores the function of vibration-based assessment methods in treatment planning and how they support ongoing research and development initiatives. Additionally, the development of this important field is clarified by discussing the historical background and current bone mechanics research initiatives. The goal of the review is to present a comprehensive understanding of vibration methods for assessing bone healing and their possible applications in clinical practice and research. The outcomes of this review state that the non-invasive techniques help clinicians make well-informed treatment decisions by offering insightful information about bone mechanics. In addition, the review highlights the potential influence of vibration methods on clinical practice and research, indicating potential for improving orthopedic care.

This work presents a framework for integrating processes in hybrid manufacturing that utilizes the strengths of each process. This work focuses on hybrid methods such as ''fused deposition modelling'' and ''CNC machining''. The hybrid technique is built on a system that creates a framework for interrelationships, allowing effect and value to be understood and appraised. The analytic hierarchy process (AHP) organizes decision making, using what has been learned about the previous procedures to successfully component complexity management for effective design and manufacturing the most valuable element. The prime focus of this study is to improve a method for selecting process parameters, evaluating the mechanical and physical properties of specimens creating using the fused deposition modelling technique. Before utilizing FDM to create a product, a number of parameters must be established. The component orientation, infill pattern, fill density, layer thickness, printing speed, and shell thickness are some of these variables. There are certain outputs from the final component that can be noticed, examinations and measures. Some of these replies include the final product's dimensions and mechanical characteristics, such as its tensile strength, impact strength, and compression strength. In this study, the link between the process variables of a 3D printer employing fused deposition modelling (FDM) technology and a CNC machine for the output was examined. The substance used was PLA plastic, which was widely used in the sector. Knowing the connection between the parameters and the outcomes enables the production of the final product to satisfy user requirements. Responses were gauged and evaluated for dimensional correctness and product robustness. Dimensions of mechanical test specimens' gauge areas (tensile strength, impact strength, and compression strength) fabricate in comparison with the measurements specified by (ASTM 638-03, ISO 180), and (ASTM D695 ) correspondingly also served as a measure of dimension correctness. The analytic hierarchy process (AHP) to identify the operation parameters that have an effect on the mechanical and physical attributes of the specimens.

The aim of this study is to modify the performance of PMMA which is suitable for denture application. It is desirable for Polymethyl methacrylate (PMMA) to have high mechanical properties for dental applications like denture. The reinforced of PMMA with 1 wt.% glass fiber and different weight percentage of Y2O3 were estimated. Increase the mechanical and physical properties were found with increased the weight percentage of Y2O3. The maximum impact strength was obtained by using 6% Y2O3 with 1 wt.% glass fibers. The physical properties, which are included density and water absorption increased with increased the weight percentage of Y2O3 in PMMA. Furthermore, the improvement in impact strength was obtained at 6% Y2O3 was 45.48%. Finally, the SEM results show the homogenous distribution of Y2O3 in PMMA.

In this study, a composite coating of polyurethane resin with (CaSO4) was prepared using different proportions of ceramic powders (0, 5, 10, 15 and 20 wt.%) as a strengthening technique in the polymer matrix using adventitious coating on the ceramic substrate. Micro-hardness, porosity, FTIR, SEM, and microstructure of the composite surface were performed. Mechanical properties (hardness test) know that the highest value (88) is obtained at 15 wt % calcium carbonate. In addition, the structure testing results of both SEM and optical microscopy images of the coating revealed good cohesion and uniformity in the distribution of the ceramic powder, indicating that the composite coating structures are dense, compact, coating is around (500 nm) thick while the mean particles size distribute in to (83.01 μm) and (213.67 μm) and do not contain significant porosity value (3.2%) appear at (20 wt.% CaSO4) of carbonate compared to the uncoated sample (18%) .