Study of temperature in the edge milling of carbon fiber-reinforced plastic (CFRP)/Ti6Al4V stack material for aerospace industry

Abstract

With the advances of new technologies and new materials, aerospace, military and commercial aircraft industries are looking to decrease the fuel consumption by reducing weight into their structures and components. Hybrid or stacks of materials are used more often in airframes because of their outstanding mechanical properties such as high strength/weight ratio and, excellent corrosion and fatigue resistance that cannot be provided with metallic materials. Carbon Fiber-Reinforced Plastic (CFRP)/Titanium is the most used type of hybrid material for thermal-load applications in aviation, Ti6Al4V being the most popular of the titanium alloys. Usually, CFRP/Ti6Al4V plaque is assembled by rivets or bolts; however, there are some applications where both materials are bonded or cured together. Thus, the drilling process is not required as it usually happens, removing cost and weight from the airframe. The difference in machinability and the temperature invariability of each material makes achieving specified geometries and dimensional tolerances a real challenge. Therefore, this thesis studies the thermal effects on CFRP/Ti6Al4V in the process of edge milling. In particular, we study the tool-workpiece thermocouple method by using commercial thermocouples. Additionally, we study the effects of cutters while varying cutting speed, feed per tooth and radial depth of cut on the forces, roughness and tool wear for the different types of cutters. We found that, as opposed to what was previously thought, the feed factor is the most influent one regarding the cutting temperature for the CFRP and Ti workpiece instead of the cutting speed. It has been found that the temperature in the workpiece increases by decreasing feed per tooth and decreases by increasing the cutting speed, although this last factor is not as significant as the feed per tooth.

Date	27 Nov 2019
Original language	American English
Awarding Institution	École de technologie supérieure
Supervisor	Jean-François Chatelain (Supervisor) & Gilbert Lebrun (Co-supervisor)