Akademik Veri Yönetim Sistemi
APPLIED COMPOSITE MATERIALS, cilt.30, sa.1, ss.57-72, 2023 (SCI-Expanded)
Compression molded polymer composites are generally produced with small dimensions for advanced engineering applications such as microelectronics. Among a broad range of polymers, ultra-high molecular weight polyethylene (UHMWPE) rises as an excellent matrix material due to its high impact absorbing, advanced wear resistive, low friction, self-lubricating, anti-corrosion and eco-friendly properties. Although UHMWPE based composites have been widely investigated in terms of tribology, impact behavior and mechanical properties, there is a big gap in literature regarding the micro-machinability of these advanced composites. In this work, polytetrafluoroethylene (PTFE) and aramid reinforced UHMWPE composites were produced in a compression molding chamber and these specimens were subjected to micro-milling operations by using a flat micro end cutter at three different spindle speeds. Micro-machining characteristics were evaluated in terms of surface roughness and cutting temperature. From the results, surface quality is heavily affected by spindle speed, which changes the material removal mechanism from tearing to shearing at higher rates. Molding pressure is also determinant on surface roughness by means of microstructural consolidation. Regarding the filler materials, it is possible to state that there are two different roughening mechanisms after milling. In the PTFE filled composites, machined surfaces include pitting topographies due to the detached particulate PTFE. However, fiber protrusions from the matrix enhance the roughness on the machined surfaces of the aramid reinforced composites. Furthermore, filler inclusions lead to a slight increase in the cutting temperatures during the milling operations.