Evaluating the influence of reinforcing fiber type on the grinding process of PEEK’s composites

Abstract

Polyether ether ketone (PEEK) and its composites are widely used in the biomedical industry due to their superior properties. The presence of glass and carbon reinforcing particles will improve the strength of the polymers while affecting their machinability. The cutting speed, dressing speed ratio, and different reinforcing fibers were defined as input parameters. Grinding forces, specific grinding energy, surface roughness, the surface topography of the workpiece, and wheel loading ratio were selected as output parameters of this research. Surface roughness is strongly affected by heat generation in the grinding zone. The experiments showed that pure polymer, GFRP (glass fiber-reinforced plastic), and CFRP (carbon fiberreinforced plastic) induce maximum wheel loading ratio, respectively. The maximum wheel loading was calculated as 31% for pure polymer, and the main mechanism is melting. The highest cutting forces were measured when grinding pure polymer, followed by carbon, and glass fiber composites. The grinding forces were also affected by wheel loading ratio. Normal and tangential grinding forces increased up to 67% and 57%, respectively, by severe cutting conditions. The minimum specific grinding energy of PEEK and its composites was around 2.5 J/mm 3 . Additionally, increasing the cutting speed to v c = 15 m/s (despite lower inducing cutting forces) and decreasing the dressing speed ratio to q d = −0.3 surprisingly caused a rise in the roughness of the ground surfaces (for all three materials) due to a higher heat generation in the contact zone.

Investigation of the effects of reinforcement particles in polymers on their grindability in single grit scratch test

“…Kamplade and Biermann 15 showed that it could be due to an increment in the rubbing and plowing portion (the increase in normal force is higher than in tangential force at higher cutting speeds). The result conducted from the study of Khoran et al 12 also conforms with this outcome. The PEEK grinding force was higher than its composites due to more rubbing and plowing.…”

“…Comparing the specific energies of the single grit scratch test and the grinding process 8,12 shows that the specific energy of the grinding is higher than that of the single grit test. Because several mechanisms like loading influence the specific energy in the grinding process, which does not happen in the single grain test.…”

Use of Karl Fischer titration for the localized measurement of water content in FRP composite aircraft parts removed from service

“…During sample grinding, heating and an increase in the exchange surface area may occur, allowing some free water to evaporate. 73,74…”

“…During sample grinding, heating and an increase in the exchange surface area may occur, allowing some free water to evaporate. 73,74 Distribution of water content across the scrapped outlet guide vanes Mapping. In order to represent the water content distribution across an OGV blade, a NACA 4-digit airfoil is used.…”

Effect of Fiber Type and Content on Surface Quality and Removal Mechanism of Fiber-Reinforced Polyetheretherketone in Ultra-Precision Grinding

“…The results showed that as the temperature of the machining area increased, the material entered a visco-elastic state and the quality of the milled surface deteriorated. Khoran et al [ 19 , 20 ] studied the grinding performance of PEEK, carbon-fiber-reinforced PEEK and glass-fiber-reinforced PEEK. The results showed that the machining temperature had a greater impact on the surface quality of PEEK and fiber-reinforced PEEK, while when using liquid nitrogen as the coolant, the grinding surface quality was significantly improved.…”