Parameters Affecting Tool Wear other than Abrasion

Wood and wood products are generally machined before they are placed in service.Tool and tool maintenance costs contribute importantly to the total production cost in the wood processing industry.The machining of MDF (Medium Density Fiberboard) involves high temperatures and pressure in the cutting zone at and near the tool edge,because it contains wood as well as binder such as urea formaldehyde,resin,catalyst,wax,extenders and fillers etc.The machining of MDF produce more decomposition products that can adversely affect tool wear.So this paper reviews the factors responsible for the tool wear, to know the effects of high temperature sulfidation and oxidation and halides specifically chlorine (Cl). The element analysis from thermo gravimetric analysis (TGA) showed that the chlorine was available as Cl-, Cl2 or HCl to react with C2 (Tungsten carbide 6% cobalt) in gas phase reaction. The weight loss of C2 in TGA is characteristics of volatile corrosion products such as CoCl3 (Cobalt trivalent chloride) as the result of oxidation chlorination of cobalt. It is seen that, diffusing element boron to the substrate surface of a metal form a chemical layer which increases the tool life by reducing cobalt binder removal.