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Optimisation of variation coolant system techniques in machining aluminium alloy Al319

Zainal Ariffin S., Efendee A. M., Redhwan A. A. M., Alias M., Arifuddin A., Kamrol Amri M., Mohd Ali M., Khalil K., Aminullah A. R. M., Hasnain A. R., Baba N. B.

Journal of Achievements in Materials and Manufacturing Engineering

2022

Vol. 113, nr 2

72--77

Purpose: Cutting parameters are often chosen for machining by machine operators in the industry. The experience and efficiency of the machine operator in producing a quality product are frequently used to decide parameter selection - low productivity results from improper parameter selection, inefficient machining, and technological issues. Today's key issues in the machining industry are focusing on increasing machining performance on surface roughness while minimising coolant usage. The study's objective is to enhance the performance of the nozzle lubrication system during the turning operation of an aluminium alloy 319 workpieces (Al319) to generate good surface roughness by applying turning parameters such as cutting speed, feed rate, and the depth of cut. Design/methodology/approach: Response Surface Method (RSM) was used to create the experimental method for this investigation, carried out using a CNC lathe machine with two axial movements and a wet cooling nozzle with a size of 1.0 mm. Synthetic soluble lubricants, Al2O3-coated cemented carbide inserts, and Aluminium alloy 319 were utilised as cutting tools and workpiece materials. Findings: To study the influence of cutting parameters on surface roughness, the Analysis of Variance (ANOVA) approach was utilised while the response surface method was performed to achieve an optimum machining performance (RSM). When comparing dry and wet cooling systems, the size of 1.0 mm nozzle shows appropriate surface roughness. According to the ANOVA analysis, the key factor impacting the surface roughness as machining performance in lubrication technique experiments was the utilisation of 1.0 mm nozzle size. Research limitations/implications: The findings of combination machining parameters at a cutting speed of 270 m/min and a cutting depth of 0.60 mm at a feed rate of 0.08 mm/min offered the best results, achieving a surface roughness, Ra of 0.94 μm. Practical implications: The use of coolant size nozzle 1.0 mm technology combined with the use of correct machining parameters can improve machining cuts. Originality/value: The novel size of 1.0 mm nozzle in this current research is also valuable for reducing and increasing productivity in the machining business, as well as reducing dependency on machining operators' experience and abilities.

Stress homogeneity in adhesive layer of composite double lap joint under dynamic shear loading

Saleh P., Challita G., Hazimeh R., Khalil K.

Composites Theory and Practice

2015

R. 15, nr 2

101--106

The main purpose of this work is to numerically investigate the shear stress homogeneity in the adhesive layer of a double lap joint specimen subjected to dynamic shear loading using the Split Hopkinson Pressure Bar technique (SHPB). This homogeneity is measured through a coefficient defined by the ratio of the standard deviation over the average shear stress in the adhesive layer. Three types of fiber textures of carbon-epoxy composite adherents were examined: unidirectional laminates, 2.5 D interlock H2 and 3D orthogonal. The influence of many parameters related to the adhesive was studied for the three types of composite adherents. For the same percentage of carbon fibers, it was found that the unidirectional composite substrates give the best homogeneity. Moreover, a thicker, shorter and softer adhesive layer ensures the best shear stress homogeneity for all the three types of substrates. The software used for this study is ABAQUS.

Głównym celem pracy jest badanie numeryczne jednorodności naprężenia ścinającego w warstwie przyczepnej próbki z podwójnym połączeniem zakładkowym poddanej dynamicznemu obciążeniu ścinającemu przy użyciu pręta Hopkinsona (SHPB). Jednorodność tę mierzy się poprzez współczynnik definiowany przez stosunek odchylenia standardowego do przeciętnego naprężenia standardowego w warstwie przyczepnej. Badano trzy typy tekstur włókien kompozytów węglowo-epoksydowych: laminat jednokierunkowy, 2,5-wymiarowy laminat o gęstym splocie H2 oraz laminat trójwymiarowy ortogonalny. Dla tych trzech typów kompozytów badano wpływ wielu parametrów powiązanych ze spoiwem. Stwierdzono, że przy tym samym udziale procentowym włókien węglowych najlepszą jednorodność można uzyskać w przypadku jednokierunkowych laminatów. Co więcej, grubsza, krótsza i bardziej miękka warstwa przyczepna zapewnia najlepszą jednorodność naprężenia ścinającego dla wszystkich trzech typów substratów. Do badań użyto pakietu programów ABAQUS.