An Experimental Investigation on Hybrid Nano fluid with Vegetable Oils as a Cutting Fluid using Minimum Quantity Lubrication

Hard machining plays a vital role in traditional machining for high productivity and for complex jobs. In this type of machining cutting, fluid has major factor property of cutting fluid to minimize the friction and to reduce the temperature at machining area. In the traditional approach, most of the time industries using mineral oils for lubrication or as cutting fluid in machining but a due large amount of using of mineral oils a large amount of oxidation happens which is toxic and harmful to workers. To overcome these effects experiment is done by using vegetable oil with the addition of nanoparticles which enhanced the properties of cutting fluid. The experiment is done on Mild Steel with working pair of Al2O3 and MoS2 nanoparticles in palm oil. Output is taken from this experiment in parameters like cutting forces, surface temperature, tool temperature, and surface roughness. This method gives better results than dry machining.

TRIBOLOGY AND TOPOGRAPHY OF HARD MACHINED SURFACES

In machining automotive industrial parts by hard machining procedures, the topographic characteristics of high accuracy surfaces have high importance. In this paper 2D and 3D surface roughness features of gear bores machined by hard turning and grinding are demonstrated. The 3D roughness parameters, which are considered as more exact than the 2D parameters, were compared to the 2D ones, which are used more widely in industrial practice. The analyzed machining procedure versions were ranked based on the topographic parameters determining the tribological (wear and oil-retention capability) characteristics of the different surfaces.

High performance peel grinding of steel shafts using coarse electroplated CBN grinding wheels

Grinding is widely known for its low material removal rates and high surface quality. However, recent developments in production processes for cubic boron nitride (CBN) abrasive grains have led to commercially available grain sizes larger than 300 µm. These superabrasive CBN-grains allow higher material removal rates during grinding of hardened steel components. Currently, these components are pre-machined with turning processes before hardening and finishing the work piece by grinding. However, the turning process can be eliminated by grinding with coarse CBN-grains since higher depths of cut are achievable when machining hardened components. This paper explores the limits of grinding wheels using grains with a size of B602 during soft and hard machining in comparison to conventional B252 grains. It is shown that the use of coarser grains leads to lower process forces, higher (tensile) residual stress and higher surface roughness. Residual stress and surface roughness are of less importance as these grains are to be used mainly in roughing operations with ensuing finishing operations for the required surface properties. Over all investigations, especially in hard machining, neither grain nor tool wear was observed for the B602 grains, whereas the B252 tool was severely clogged during the experiments. Additionally, the grinding force ratio indicates that the coarse grain tools have not yet reached their productivity limit as it increases over all investigated feeds. This indicates improving tool performance with lower amounts of rubbing for increasing feed rate during hard grinding and shows the potential for the industrial use of higher feed rates with larger grains.