Influence of thermoplastic nodules on drilling quality

Delamination analysis during long-fiber composite drilling

Figure 1 - View of the composite sheet clamping system on the milling machine table

Figure 4 - Variation of delamination factor at hole exit as a function of feed speed for N &#61; 1050 rpm and manufacturing process

Figure 5 - Variation of delamination factor at hole exit as a function of rotational speed for both manufacturing processes. With a feed rate f of 0.1 mm/rev

Figure 9 - Evolution of optimum feed speeds as a function of optimum rotation speeds for the two plates studied

Figure 10 - Hole condition after drilling an autoclaved plate at a feed rate of 0.023 mm/rev and N ≍ 500 rpm (a) at the hole outlet and (b) at the hole inlet.

Figure 11 - Evolution of thrust force Fz as a function of (a) tool diameter for N &#61; 1500 rpm, f &#61; 0.01 mm/rev and (b) feed speed for N &#61; 1500 rpm, d &#61; 6 mm

Figure 12 - Variation of the specific cutting pressure ratio of the two materials studied as a function of feed speed for N &#61; 1500 rpm and a tool diameter of 6 mm.

Figure 13 - Variation of the specific cutting pressure ratio of the two materials studied as a function of drill diameter for f &#61; 0.01 mm/rev and N &#61; 1,500 rpm

Figure 14 - SEM photos of the hole exit condition for cutting parameters d &#61; 6 mm, N &#61; 1500 rpm and f &#61; 0.02 mm/rev with (a) plate type M21-T700GC and (b) plate type EH25-T2H respectively

Figure 15 - Evolution of delamination factor Fd at hole exit as a function of tool feed rate f with d &#61; 6 mm and N &#61; 1500 rpm

Figure 16 - SEM photos of machined surfaces (hole wall) with (a) M21-T700GC plate and (b) EH25-T2H plate for cutting parameters d &#61; 6 mm, N &#61; 1500 rpm and f &#61; 0.02 mm/rev respectively.

Figure 17 - SEM photos of thermoplastic nodules in the M21-T700GC material with (a) global view and (b) zoom of the surrounded area on the global view [46].

Figure 18 - Evolution of roughness as a function of feed rate per revolution for both materials