The relationship of cutting force with hole quality in drilling process of AISI H13 steel

The harmony of the drilling machine-cutting tool-work piece is very important for producing the machine part with the ideal dimensions. For this purpose in this study, the effect of cutting forces on hole quality (surface roughness, diameter deviation and circular deviation) was investigated by 14 mm diameter uncoated and (AlCrN monolayer) coated carbide drills for drilling AISI H13 hot work tool steel on vertical machining center. Four different cutting speeds (60, 75, 90 and 108 m / min) and three different feed rates (0.15, 0.20 and 0.25 mm / rev) were used in the experiments. Cutting forces have been found to be effective in improving hole quality. Better hole quality has obtained with coated drills than uncoated drills in experiments. It has been observed that coated drills have the effect of improving the hole quality due to the operation with less cutting force and better chip evacuation

Production of sage, oregano and rosemary under shading conditions and the effects of light on growth and essential oil properties

Intercropping and agroforestry systems provide sustainable land and resource use efficiency, however, shading conditions generated by the base crop or tree cover is a restricting factor on the growth of the intercrop and productivity of the system. Hence, a two-year field experiment was carried out to assess the yield, essential oil properties, morphological changes, and anatomical adaptation of the shade-exposed sage (Salvia officinalis L.), oregano (Origanum onites L.) and rosemary (Rosmarinus officinalis L.) plants. Plant height, leaf area, chlorophyll content, herbage yield, essential oil content and biochemical profile of the selected species were comparatively examined under open-field, 40% and 75% shading conditions. Initially, after the seedlings were transplanted to the field, a horizontal growth of shaded plants, resulted in lower plant height, then, after the plants covered the soil surface, vertical growth was observed. Overall drug herbage yield decreased by 65% due to the shading treatments in the first year whereas rosemary, sage and oregano had 20.9%, 25.3% and 40.3% lower yields respectively in the second year. Average essential oil content of low-light exposed plants increased by 23% and 41% first and second year of the experiment, respectively. A negative linear relation between α-thujone content in essential oil of sage and shading level was recorded while in contrast, carvacrol content of oregano essential oil increased by shade treatment. The results concluded that herbage yield and quality properties of shaded plants were promising, especially after the first year, considering their potential in intercropping and agroforestry systems. Since the current study represented the results for artificial shading conditions, the tree-based intercropping studies needed to be performed with these species for the final conclusion. © 2023 Elsevier B.V.The authors gratefully acknowledge the financial support of Ege University , Office of Scientific Research Projects ( 17-ZRF-028 ). A part of the data presented in the paper provided from the master thesis of Selda Şeker.17-ZRF-028; Ege Üniversites

The effect of minimum quantity lubrication under different parameters in the turning of AA7075 and AA2024 aluminium alloys

Cutting fluid application plays an important role in the improvement of cutting performance during machining processes. However, controlling the amount of the coolant used is important in terms of its effects on the environment, human health and also on the total cost of production. Another important concern is to avoid lowering the product quality and cutting tool life when the amount of coolant is decreased. The minimum quantity lubrication (MQL) method that has been developed in recent years is suitable for meeting these needs. In this study, the MQL technique was applied in the turning of AA7075 and AA2024 aluminium alloys. The samples were subjected to four different cutting speeds (150, 187.5, 240 and 300 m/min), two different feed rates (0.1 and 0.2 mm/rev) and four different flow rates (0.25, 0.45, 0.90 and 3.25 ml/min). At the end of experiments, it was observed that increased feed rate and cutting speed had a negative effect on surface quality, while increased flow rate exhibited a positive effect on surface quality. © 2015, Springer-Verlag London