This paper experimentally observed at a small level the influence of nozzle temperature change on warping deformation (WD), dimensional Accuracy (DA) and density. The materials chosen are pure PLA and advanced PLA+ specimens of rectangular shape of 63.5 mm × 9.53 mm × 3.2 mm produced by the end-user 3D printer based on fused deposition modeling (FDM). During the printing work, the nozzle temperature was conducted at twelve different values 195°C to 250°C with 5°C increments. Additionally, the infill density was set at 20% along with infill line direction of 0°, 90°, 45° and ±45°. After the fabrication, the FDM 3D printed parts naturally cooled down to room temperature at T = 23±2°C. As a result, the higher the nozzle temperature, the lower the deformed shape errors (with low uncertainty) of the specimens were. Experimental results show that the measured dimensions are always more than the original CAD file dimension along the height but less than the original CAD file dimensions along the width and length. The density measurements of both materials at 90° infill line direction have higher values compared with other directions (0°, 45°, ±45°), which have very similar results. The data and knowledge obtained from this investigation can be helpful for both an academic and an industrial perspective to set optimum nozzle temperature at small scale level and also it can be used to fabricate low-cost functional objects. Furthermore, it will also allow us to redesign the original CAD file in order to compensate the warping deformation encountered when using end-user FDM 3D additive manufacturing.

Abrasive waterjet (AWJ) cutting technology has been used extensively for the cutting and processing of almost all engineering materials because of its precise cutting technique and the lack of damage caused. Currently, the use of abrasive waterjet cutting in the natural stone industry is increasing. However, the effectiveness of abrasive waterjet cutting of natural stones is dependent on the rock properties and machine operating parameters. Consequently, this paper presents the influence of abrasive waterjet machining parameters on the surface texture quality of Carrara marble. The results have shown that the abrasive waterjet cutting process offers better cut surface texture quality of Carrara marble under certain parameter conditions as well as being more environmentally-friendly. The stand-off distance shows the opposite effect on both surface roughness and waviness. With a view to reducing the machining costs, every user tries to select the traverse rate of the cutting head to be as high as possible, but results show that increasing the traverse rate always causes a corresponding increase in terms of inaccuracy, surface roughness, R a ≈ 93.7 µm, and waviness, W a ≈ 92.6 µm. The abrasive mass flow rate is not a significant parameter during the cutting process. In all investigations, it was found that the machined surface of the marble is smoother near the jet entrance, R a ≈ 4 µm, and waviness, W a ≈ 5 µm, and increasingly becomes rougher towards the jet exit. The result also shows that the micro-hardness value of the Carrara marble was in the range of 122 HV to 124 HV.

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The current study discusses the peristaltic flow of Jeffrey fluid through a porous wall channel. Magnetohydrodynamic (MHD) effects are also considered while formulating the problem. Heat and mass transfers are discussed in the presence of activation energy and constant heat source/sink effects. A chemical reaction is also part of the analysis. The Lubrication approach is adopted for the simplification of resulting non-linear equations. MATHEMATICA command, NDSolve, is used to discuss the results graphically for various flow parameters like Hartman number $$(M)$$ ( M ) , porosity parameter $$(k)$$ ( k ) , slip parameters ($$\gamma ,{\gamma }_{1},{\gamma }_{2}$$ γ , γ 1 , γ 2 ), Schmidt $$(Sc)$$ ( S c ) , Soret $$(Sr)$$ ( S r ) and Prandtl $$(Pr)$$ ( P r ) numbers, and many others. Parabolic behavior for velocity and sinusoidal nature for heat transfer and pressure gradient is noticed. Results indicate that the velocity is greatly affected by varying values of slip parameters (γ′s) and Hartman number $$(H)$$ ( H ) . Enhancing the viscoelastic nature of fluid causes an increase in velocity. Similar behavior is noticed for velocity and temperature profiles. The decreasing trend is shown by concentration when the value of the chemical reaction and temperature ratio parameters is enhanced. Thus, the study presented in the current analysis can be used to study many human physiological systems especially, the blood flow. Since Jeffrey's fluid exhibits the same characteristics as observed for blood.

Electrical discharge machining is an old technology that has been used for old manufacturing processes. Nowadays, the modernized version of the machine is used to manufacture different objects using a wire feed. The parameters in which the machine operates have diverse effects on product quality and surface finish. This paper investigates the performance of a wire electrical discharge machining process for different wire feed rates. The process is a non-traditional machining method. Several tests have been performed considering a carbon steel 1017 and aluminum alloy 6060 machined via Wire-EDM. By using different wire feed rates (3 mm/min, 5 mm/min and 7 mm/min), the average surface roughness, R a , has been investigated in this study. Results show that the wire feed rate is a significant variable to the surface quality finish. The surface roughness of the test target materials increased as this variable increased. The present study recommends setting the wire feed rate as low as possible with the aim of improving results in the surface quality finish. The obtained results and some of the most necessary parameters affecting the manufacturing process of wire-EDM are briefly defined and are then discussed in detail in this study.