Analysis of deburring effectiveness and surface layer properties around edges of workpieces made of 7075 aluminium alloy

This paper aims to present a comprehensive analysis of deburring effectiveness and surface layer properties after deburring process by wire brushing from milled 7075 aluminium alloys objects. Edge states (rounding, chamfering), surface roughness around the edge, microhardness and residual stress distribution were analyzed.

During the machining process, undesirable phenomenon occurs, which is the formation of burrs at the edges of workpieces. They occur in most elements formed by machining. There are many methods that can be used for deburring, but in the case of large components, typical of aerospace industry, using certain methods becomes difficult or uneconomic. Taking advantage of the fact that a part is mounted on the machine, it is advisable to make deburring operation the last action. This operation can be carried out by wire brushing.

On the basis of conducted studies, it was demonstrated that it was possible to choose such technological brushing conditions as to ensure an effective process of deburring, form appropriate edge state and generate the desired surface layer properties.

The method presented in the article allows for efficient, automatic deburring, especially for large components made of 7075 aluminium alloy. This eliminates manual, time-consuming methods of removing burrs by locksmiths. Moreover, the results allow to evaluate changes occurring in the surface layer after brushing process.

Results of brushing experiment provide full information on selection of technological parameters to obtain the required surface roughness and edge state. Moreover, analysis of surface layer properties (microhardness, residual stress) allows to assess the degree of impact hitting fibre on the workpiece.