Feed Rate Force Research Articles

Experimental modeling and optimization of surface quality and thrust forces in drilling of high-strength Al 7075 alloy: CRITIC and meta-heuristic algorithms

Al 7075 is a renowned high-strength engineering material used in automotive and aerospace applications, wherein many functional cylindrical parts are subjected to internal or external loads. Engineered parts with form errors (cylindricity CE and circularity error Ce) result in undesirable vibration and high deformation in rotating parts. In addition, reduced surface roughness (SR) and thrust forces (TF) are essential to limit the secondary process (namely, polishing) and power consumption. Experiments are performed based on central composite design considering drilling parameters (point angle, cutting speed, and feed rate) as inputs and output performances as CE, Ce, TF, and SR. It is noted that, except feed rate for Ce, all other parameters are found significant toward the output performance. Also, prediction accuracy with ten random experimental cases resulted with the percent error of 8.4% for SR, 5.41% for TF, 10.64% for Ce, and 10.35% for CE, respectively. Continuous ribbon-like chips at higher cutting speed, loose fragmented chips at higher feed rate, and increased arc length and radius at higher point angle were observed from the chip morphology analysis. Criteria importance through inter-criteria correlation (CRITIC) method applied to determine the weight fractions for Ce, CE, TF, and SR was found equal to 0.2802, 0.1991, 0.3293, and 0.1914, respectively. Four algorithms (genetic algorithm GA, particle swarm optimization PSO, teaching learning-based optimization TLBO, and JAYA algorithm) were applied to determine the optimal drilling conditions. JAYA algorithm determined optimized drilling conditions ensure predicted output values found close to experimental values with an acceptable percent error of 10.8% for Ce, 8.9% for CE, 6.73% for SR, and 3.51% for TF, respectively.

Analysis of the micro turning process in the Ti-6Al-4V titanium alloy

The great challenge of the modern industry is carrying out an online prediction in the shop floor during the machining to define the exact instant of tool breakage and simultaneously improve the quality of manufactured products. This work shows a study to examine the effect of the feed rate, depth of cut, cooling system, and type of tool on the responses: surface roughness, passive force (Fp), feed rate force (Ff), cutting force (Fc), and micro hardness in the turning of Ti-6Al-4V titanium alloy. Experimental tests were carried out with workpieces 4 mm in diameter, and the surface roughness, micro hardness, and cutting efforts were analyzed. The analysis of variance was used to define the influence of input parameters on the responses. The results showed that the lowest surface roughness was achieved using the carbide tool with code TPMT and the lower input parameters, but the most important parameter was feed rate. The cutting efforts were influenced by feed rate and depth of cut. On the other hand, the cooling system does not show good efficiency in the cutting efforts. However, the geometry of the tool and the Minimum Quantity Lubrication system were more effective to cause the hardening in micro scale at the surface of the material.