Site Loader
Get a Quote
Rock Street, San Francisco

1.7.2 Selection of Fluid for Carrying the Solid Lubricant
Cutting fluids may consist of pure oil, a mixture of two or more oils or a mixture of oil and water 25. Oils are generally divided into two groups: the fixed oils and the mineral oils. The fixed oils have greater “oiliness” than the mineral oils, but they are not so stable and tend to become gummy and decompose when heated. In this group are animal and vegetable oils. On the other hand, the mineral oils group is obtained from crude petroleum mined from the oil fields. The most common type of lubricant used for cutting is soluble oil.
There is a huge potential for utilizing vegetable oils as cutting fluids in manufacturing sector 26. Rapid work is in progress in the last five years to develop environmental friendly cutting fluids based on various vegetable oils. Most of the works reported, were on soya bean, sunflower and rapeseed oils.
The boric acid powder and canola oil lubricant mixture demonstrates multifunctional lubrication performance, where surfaces are separated by a liquid lubricant film and protected by solid powder. Boric acid powder (H3B03) is a lamellar solid that has low frictional behaviour and shear strength.
1.8 OBJECTIVES OF THE PRESENT WORK
Nano-crystalline Boric acid powder with SAE 40 oil as carrying medium is one of the alternatives to other lubricants. But as the size of the solid lubricant is decreased from 538 nano meters to 50 nano meters, there were opposing results in the tribological perspective. The pin on disc (POD) tests revealed an inverse relationship between coefficient of friction and the H3BO3 particle size up to zero microns. In fact some experimental results were supporting the same phenomena in the sub-micron range of the size of the solid lubricant. In some of the metal cutting investigations, it was found that size of the solid lubricant. In some of the metal cutting investigations, it was found that the coefficient of friction is high when nano sized MoS2 is used as solid lubricant as compared with that of the mixture of nano sized MoS2 and micro sized Ti. That means, as the properties of materials are changing with respect to its spatial dimension from micron to nano size, the performance of solid lubricant in the metal cutting is a matter of research. In fact, there should be more insight into the behaviour of the graphite as the solid lubricant in its nano regime in the machining of metals.
The present work aims at
(i) Finding out the optimum percentage of Tio2(µm) and nano-crystalline H3BO3 powder to be mixed in the carrying medium (SAE 40).
(ii) Investigating the behaviour of Tio2(µm) and nano-crystalline Boric acid as lubricant during the turning of EN24 under varying machining conditions.
(iii) Developing a ANN in order to mitigate the vagueness in the experimental data.
(iv) Creating expressions of the experimental results using Regression analysis and develop a set of relations which could be used by general users as well as the manufacturers par se.

Post Author: admin