Purpose The purpose of this paper is to investigate the effect of graphene platelets (GPLs) on the low-speed contact between a mass and surface of a multi-layer polymer beam. Design/methodology/approach This problem is primarily organized by first-order shear deformation beam theory and nonlinear Hertz rule. GPLs are distributed along the beam thickness direction. The Halpin–Tsai micromechanics model is applied for computing the effective Young’s modulus of the GPLs/polymer composites. In the formulation process, the principle of conservation of energy is first used and the histories of results are extracted using the separation of variables and Runge–Kutta method. Findings In comparing the responses with the available data, a good agreement is observed. The effects of the weight fraction and distribution pattern on the impact response of polymer beam reinforced with GPLs are studied. Results show that contact force is increased, contact time and beam recess are decreased with increasing of weight fraction of GPLs. Also, among the different distribution patterns, the contact force depended on value of GPLs at the point of contact. Originality/value The effects of GPLs addition on the multi-layer polymer beam has a novelty in impact problems.

Sheet metal is widely used in industry and in different production processes. The present work aims to reduce the bending force in the air-die bending process. Different mild steel sheet thicknesses (0.5, 0.75, 1, and 1.25 mm) were considered, and two techniques were proposed. The first technique involves an annealing process, while the second one considers cutting a rectangular hole along the bending line. The bending stress was calculated using Autodesk inventor software. The results revealed that the annealing process can provide significant ductility improvement and hence bending force reduction, and that annealing time is an important factor that influences ductility development. Moreover, cutting a hole along the bending line could reduce the bending stress and consequently the bending force. The study also reported that increasing the thickness beyond a specific value could result in a reduction in bending force instead of an increase, which is attributed to a temperature increase in the sheet and bending tool.

The aim of the present study is to facilitate the machining process of cast steel (HSS) through cooling and lubricating by compressed air with liquid in three directions and consisting of (oil, soap, carbolic acid, and sculpture) and was compared with the lubricant process in one direction and at different cutting speeds (2.08, 6.25, 10.4, and 14.16 m/sec). The Auto Desk Inventor programme is used to simulate the cutting process by applying cutting forces to the tool's shear surface. The interface equipment is used to measure cutting tool strains by the response of a strain gauge and the Arduino equipment to measure cutting tool temperature. In addition, the tool strain equations were used assuming that the cutting tool is fixed between the two walls (fixing region and surface of the workpiece) to get the best results at the same speed. The results refer to the lubricant in three directions, which is better than one direction due to decreasing cutting tool strain, reaction of cutting force on the shear surface of the cutting tool, and cutting tool temperature. The experimental results show that a cutting speed of 10.4 m/sec is the best for the cutting process. Furthermore, the numerical results are converged with practical results in a small correction factor (0.428), preventing the tool from vanishing.

Tool wear is a major problem in machining operations because the resulting material loss gradually changes of the machine tool. There many factors may leads to material loss like; friction, corrosion, and also it’s happened by rubbing during machining processes between the work piece and the tool. Dimensional accuracy of the work piece, and also the surface finish will be reducing by tool wear. It can also increase cutting force. In this study, we focused on the effect of the coating process on crater wear problems. Crater wear is caused by the flow between the chip and the rake face of the tool, whereas flank wear is caused by the contact between the tool and the work piece. In reducing crater wear, aluminum titanium nitride (AlTiN) using Al0.67 Ti0.33 in cathodic arc plating system is considered effective as a tools coating material. In reducing flank wear, AlTiN is also deemed as the best tool coating material. Experimentally, the use of Ti/AlTiN-coated tools has been proven effective in reducing crater wear. In this study, the roughness Ra values of the (Ti/AlTiN) coatings were (0.14, 0.15, 0.23, 0.02, 0.21) µm at values of layers thickness (1.138, 1.518, 1.735, 2.717, 3.0818) µm, respectively. The lowest COF appeared at thickness 2.717 µm and the high coefficient of friction of the Ti/AlTiN coating was a result of high roughness and the large contact surface area of the system coating steel ball. The two most important parameters used to measure crater wear are length and width of wear.