Deformation of Exposed Tool Parts for Crushing of Undesirable Advance Growth

Abstract

Abstract Tools for crushing of undesirable advance growth and mulching wood are subjected to heavy wear in operation with the need for their frequent replacement shortly after deployment. It is important to address the problem of their wear due to price of tools, as well as the time necessary for their replacement. Tool life is shortened because of deformation taking place due to the loss of wolfram-carbide (WC) tips, what is an undesirable phenomenon. Solutions for increasing the tool lifetimes were designed on the basis of analysis of wear mechanisms that cause this deformation. Furthermore, effect of deformed layer was evaluated by measuring hardness and microhardness. It was found that there was a strain hardening the surface due to cyclic loading. Size and extent of deformation of the entire tool with the loss of material on the functional part were documented using an optical scanning sensor system. Effect of the deformation on the material structure change, as well as topography and extent of surface area affected by abrasive wear under impact loads, were assessed by means of light and electron scanning microscopy. On the basis of these analyses, an option for increasing the lifetime of exposed areas on the tool by application of hardfacing to increase the tool wear resistance was proposed. Prerequisite for extending their work lifetime in the field is creation of a sufficient coarse layer or multiple layers of wear resistant material at specific tool areas.