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Improving surface integrity is an important issue to enhance wear resistance and fatigue life of the end product. Thus, a 3D elliptical vibration method is represented to evaluate its effect on the parameters of surface integrity in boring process. The operation is carried out on a titanium cylinder in two methods of conventional and 3D elliptical ultrasonic assisted boring. After the machining, surface roughness, microstructure changes, and microhardness of the cut surfaces are examined. The results show that 3D vibration causes the depth of microstructure changes to be less than conventional boring, while it increases the surface hardness, more. In addition, this method almost eliminates the effect of cutting parameters on surface roughness by producing micro-textures on the surface.

Analysis of the surface quality of workpiece is one of the major works in machining operations. Variations of cutting force is an important factor that highly affects the quality of machined workpiece during operation. Therefore, investigating about the variations of cutting forces is very important in machining operation. In this paper, we employ fractal analysis in order to investigate the relation between complex structure of cutting force and surface roughness of machined surface in end milling operation. We run the machining operation in different conditions in which cutting depths, type of cutting tool (serrated versus square end mills) and machining conditions (wet and dry machining) change. Based on the obtained results, we observed the relation between complexity of cutting force and surface roughness of generated surface of machined workpiece due to engagement with the flute surface of end mill, in case of using square end mill in dry machining condition, and also in case of using serrated end mill in wet machining condition. The fractal approach that was employed in this research can be potentially examined in case of other machining operations in order to investigate the possible relation between complex structure of cutting force and surface quality of machined workpiece.

Analysis of the machined surface is one of the major issues in machining operations. On the other hand, investigating about the variations of cutting forces in machining operation has great importance. Since variations of cutting forces affect the surface quality of machined workpiece, therefore, analysis of the correlation between cutting forces and surface roughness of machined workpiece is very important. In this paper, we employ fractal analysis in order to investigate about the complex structure of cutting forces and relate them to the surface quality of machined workpiece. The experiments have been conducted in different conditions that were selected based on cutting depths, type of cutting tool (serrated versus. square end mills) and machining conditions (wet and dry machining). The result of analysis showed that among all comparisons, we could only see the correlation between complex structure of cutting force and the surface roughness of machined workpiece in case of using serrated end mill in wet machining condition. The employed methodology in this research can be widely applied to other types of machining operations to analyze the effect of variations of different parameters on variability of cutting forces and surface roughness of machined workpiece and then investigate about their correlation.

The needs to rapid manufacture of automotive components have led to the extensive uses of high-speed drilling in hole-making operation. However, issues such as uncontrollable thrust force and hole quality need to be addressed effectively in order to have full benefit of high-speed machining. Modeling the effect of drilling parameters on the machining responses can be a useful approach in controlling the thrust force and surface quality of the hole. This article reports on the development of mathematical models for thrust force ( Ft) and surface roughness ( Ra) during high-speed drilling of Al–Si alloy using uncoated carbide tools. Central composite design coupled with response surface methodology was used to predict the Ft and Ra values in relation to the primary machining variables such as cutting speed and feed rate. Second-order polynomial models were developed for both responses, and the adequacy of models was verified by analysis of variance. Results show the goodness of response surface methodology in the development of mathematical models in explaining the variation of thrust force and surface roughness by relating them to the variations of cutting parameters. In the developed models, linear effects of cutting parameters have the highest contribution to the thrust force model, while their quadratic effects are the significant terms influencing the surface roughness. Consequently, the optimum cutting condition was predicted at the high and low levels of cutting speed and feed rate, respectively.

Surface roughness is an important output in different manufacturing processes. Its characteristic affects directly the performance of mechanical components and the fabrication cost. In this current work, an experimental investigation was conducted to determine the effects of various cutting speeds and feed rates on surface roughness in turning the untreated and Sb-treated Al-11%Si alloys. Experimental trials carried out using PVD TIN coated inserts. Experiments accomplished under oblique dry cutting when three different cutting speeds have been used at 70, 130 and 250 m/min with feed rates of 0.05, 0.1 and 0.15 mm/rev, whereas depth of cut kept constant at 0.05 mm. The results showed that Sb-treated Al-11%Si alloys have poor surface roughness in comparison to untreated Al-11%Si alloy. The surface roughness values reduce with cutting speed increment from 70 m/min to 250 m/min. Also, the surface finish deteriorated with increase in feed rate from 0.5 mm/rev to 0.15 mm/rev.

The motivation to replace steel and cast iron with Al–Si alloys for automotive components is part of the attempt to improve fuel economy and reduce emissions. In relation to that, the application of high-speed drilling is considered one of the most-used operations in hole making for automotive parts due to its ability to reduce lead time without sacrificing the hole quality. However, this advantage was offset by the creeping problems encountered during high-speed drilling. Although this issue is addressed accordingly, problems like uncontrollable surface integrity and poor hole quality still exist. Surface integrity studies involved the investigation of surface roughness, metallurgical changes and microhardness of the subsurface of the drilled hole. Significant alternations with respect to the loss of mechanical properties have been observed from the microhardness and microstructure analysis of the drilled hole. Results from this study showed that, in general, drilling parameters have significant effects on the surface quality and integrity of the drilled hole during high-speed drilling of Al–Si using an HSS drill.

Superalloys such as Inconel 718 have high strength at elevated temperatures, which make them attractive towards various applications in aerospace industry. However, these materials are considered difficult to machine materials. The state of a workpiece surface after machining is definitely affected by cutting parameters, such as cutting speed, feed rates, drill types and drill geometries. Drilling tests, at different spindle-speed, feed rates, drills and point angles of drill, were conducted in order to investigate the effect of the above parameters on the quality of machined holes and surface integrity of Inconel 718. The quality of machined holes was evaluated in terms of the geometrical accuracy and burr formation. Surface integrity involved the aspect of surface roughness, metallurgical alterations and microhardness of the substrate of the hole surface. High hole quality was observed even at holes produced using worn tools, in relation to dimensions, surface roughness and burr height. However, microhardness measurements and microstructural analysis of work-piece showed significant microstructural changes related with a loss of mechanical properties. In general the cutting parameters have significant effects on the surface quality and surface integrity when drilling Inconel 718 using uncoated carbide drill.