FEM-based comparative study of SQUARE & RHOMBIC INSERT machining performance during turning of AISI-D3 steel

Nowadays, employment of the Finite Element Method (FEM) in machining simulation is a common practice to decrease development times and costs, as well as to investigate numerous parameters that affect machining processes. In the present work, the 3D modelling of AISI-D3 hard turning with both square and rhombic inserts is being presented by utilizing a commercially available Finite Element Analysis (FEA) software. Eighteen tests were carried out based on cutting conditions that are recommended for the used tools. Specifically, three levels of cutting speed (75m/min, 110m/min and 140m/min), three levels of feed (0.12mm/rev, 0.16mm/rev and 0.20mm/rev) and depth of cut equal to 0.40mm for all tests, were applied. In order to describe the complex factors that define the model, such as the friction forces, the heat transfer and the pressure due to contact between the tool and the workpiece, a number of acknowledged models were utilized. A comparison of the performance between the two types of tools was made with respect to the developed machining forces and temperature distribution on the workpiece. The findings of the investigation indicate that the specific square tools produce higher values of forces compared to the rhombic ones and approximately the same temperature patterns on the workpiece. The average increase on the produced cutting forces is about 26.4%.

Enhancement of Surface Quality of AISI-D3 Steel after Electrical Discharge Machining (EDM) with Aluminium Powder Mixed in the Dielectric

Electrical Discharge Machining is an advanced machining method with various advantages, as a result of which, its use is becoming more & more widespread. This process is one of the modern machining processes which is characterized by the absence of plastic deformation and chip formation. The advancement of this process may further be enhanced by utilizing powder particles within dielectric medium that is designated as Powder Mixed Electrical Discharge Machining (PMEDM) process. In the current study, to enhance the surface roughness (SR) of AISI-D3 tool steel using Copper and Brass as electrode and Aluminium (Al) as powder by utilising PMEDM process, an experimentation has been carried out. During experimentation, pulse on and off time, peak current and powder concentration are considered as input process parameters. From the experimental results, it is noted that with mixing of aluminium powder in dielectric medium, surface roughness has increased significantly. Moreover, it is seen that powder concentration of 1 g/l at 1 A peak current giving better surface quality of AISI-D3 steel. This indicates the enhancement of Electrical Discharge Machining (EDM) performance dispersing aluminium powder in dielectric fluid.