This paper studies, the effect of input parameters (cutting speed and feed rate) on the output parameters (cutting special energy and surface roughness) in machining of ADI cost iron and 42CrMo4 steel and the MACHINABILITY of these materials compared. Based on the results it was found that ADI cutting special energy is greater than 42CrMo4 steel and with increasing cutting speed in both types of materials, cutting special energy decreases. Also, the results show that ADI surface roughness is much less than the surface roughness of 42CrMo4 steel parts. The comparison was determined with increasing feed rate cutting special energy for both materials decreased and surface roughness of machined components increase.

Recently, hard turning has become an interesting method for manufacturers as an alternative to the grinding process due to its superior features such as good surface quality, good productivity, lower production costs, lower power consumption, and shorter processing time. Despite its considerable bene ts, hard turning is a di cult process that needs advanced cutting inserts such as ceramics and cubic boron nitride. However, these cutting inserts are costly and should be used properly by choosing appropriate machining parameters. In the presented work, the hard turning process was employed to investigate the MACHINABILITY of AISI S1 cold work tool steel using a cubic boron nitride insert. The relation between machining parameters, namely depth of cut, cutting speed, and feed rate, on the responses such as power consumption, surface roughness, and machining sound was found using a full factorial orthogonal array of response surface methodology. In addition, analysis of variance was used to identify the most important machining parameters that in uence output parameters. Based on the results, surface roughness was dominantly a ected by feed rate, whereas sound and power consumption were in uenced by all machining parameters, especially cutting speed and feed rate. Good agreement between the experimental and predicted values was observed.

The main goal of present work is to identify the appropriate austenitising category to achieve the austempered ductile irons with dual matrix structure having the best possible MACHINABILITY. In this regard, specimens of low-alloyed ferritic spheroidal graphite cast iron were prepared by casting process. In order to obtain a mixed ferrite-austenite structures having different volume fraction of austenite phase, samples were subjected to one of two processes: a) partial austenitising at 870 oC for various times (5 to 60 min) or b) intercritical austenitising at various temperatures (750, 765, 780 and 800 oC) for 60 minutes. After that they were austempered in molten salt at a temperature of 350 oC for one hour. During turning with a lathe equipped with a force dynamometer, the cutting forces of the workpieces were measured as a general adopted criterion for MACHINABILITY investigation. According to the obtained results, with the increase of partial austenitising time or intercritical austenitising temperature, the volume fraction of the ausferrite phase increased, but the cutting force decreased initialy and then increased. For a certain percentage of the ausferrite phase, the turning of samples prepared with partial austenitising process was associated with lower cutting force, compared to the samples obtained by the intercritical austenitising process. In general, it can be concluded that the maximum MACHINABILITY of dual matrix ductile iron austempered at 350 oC is achieved when the selected austenitising temperature and time results to creation dual matrix structure containing 39 ±  3 Vol% ausferrite phase

This paper presents the findings of experimental investigations into the effects of cutting speed, feed rate, depth of cut and approach angle on the MACHINABILITY of titanium (Grade-5) alloy. The comparison for two different cutting materials inserts, i.e. polycrystalline diamond (PCD) and cubic boron nitride (CBN) with similar tool geometry for similar machining parameters is also carried out. Design of experiment technique i.e. response surface methodology (RSM) has been used to accomplish the objectives of the experimental study. The experimental plan for four factors at three levels using face centre, and centred composite design (CCD) was employed. The results approved the approach angle as a dominant factor on the surface roughness and the tangential force evaluation as MACHINABILITY criteria. In comparison to CBN cutting insert, the PCD insert showed better surface finish and smaller cutting force in association with the parameters considered for investigation in MACHINABILITY study of Titanium (Grade-5) alloy.

In this paper, the performance of the cutting tool with nanocrystalline multilayer coatings (TiN+TiAlN) for machining of superalloy Inconel 718 in the dry and wet conditions was studied. The multi layer TiN and TiAlN with nanocrystalline structure was applied by physical vapor deposition technique (arc evaporation) on the WC-Co inserts. The results of the ball on disc wear test and the machining of superalloy Inconel 718 in wet and dry conditions indicated that the nanocrystalline coatings could produce better performance of tools in turning. Abrasion and adhesive wear resistance improved by nanocrystalline and modified Aluminum composition in TiAlN coating as well as toughness and thermal stability.

In this research, the MACHINABILITY of iron-recycled grey cast iron powder metallurgy parts is investigated. For this purpose, grey cast iron swarfs were transformed to powders by target jet milling method and were then used to prepare powder metallurgy parts in combination with commercial iron powder. Green compacts were prepared with the variables of cast iron powder percentage and compaction pressure. Design of experiments was conducted by response surface method for sintered parts with the variables of cast iron powder percentage, compaction pressure, sintering temperature and sintering time each in five levels. Regression analysis and analysis of variance were used to investigate the effect of input parameters, develop the mathematical models and evaluate the validity of the models. In the green section, MACHINABILITY was qualitatively investigated in drilling. For sintered parts, MACHINABILITY was evaluated by measuring the thrust and torque forces and the obtained surface finish in drilling. The obtained results certificated the accuracy of the extracted regression equations for predicting the machining properties of the parts. Also, the results demonstrated that the addition of jet milled grey cast iron improves the MACHINABILITY of iron-based powder metallurgy parts.

Achieving high surface quality, dimensional accuracy, and productivity in free-form and complex 3D geometries is crucial, especially in industries such as aerospace and medicine. This study investigates the effects of three modern finishing strategies—spiral, curve machining, and steep and shallow—on surface roughness, form error (as a geometric tolerance), and material removal rate. Simulations were performed using PowerMILL software, and experimental tests were conducted on a CNC milling machine. The results showed that the steep and shallow strategy delivered the best performance in terms of surface quality and geometric accuracy, achieving a surface roughness of 0.077𝜇𝑚 and a form error of 0.0184mm, with improvements of 27.49% and 76.86%, respectively, compared to other strategies. Conversely, the spiral strategy exhibited the highest productivity, with a material removal rate of 0.1325gr/s and a machining time of 30 minutes, demonstrating a 19.8% improvement in material removal rate compared to the lowest-performing strategy. These findings emphasize the importance of selecting a finishing strategy that balances surface quality, geometric accuracy, and process productivity to meet the specific requirements of each workpiece.