Figure 14
Fratographic analysis. a) General fracture behaviour of ball heads failing before reaching 107 fatigue cycles. b, c, d) Test Nr. 15 (<103 cycles) and e, f, g) Test Nr. 5 (3.28*106 cycles) b, e) Main fracture fragment (fish‒eye mode). Arrow marks fracture origin and S salt scales. c) Arrow marks fracture origin. d) Fracture origin magnified. Insert: opposite fracture surface. Arrow marks a granule, attached to large pore. The granule had not been destroyed during pressing the green body. f) Fracture origin magnified (circular line marks area in which porous regions where found). g) Magnified area showing a fine grained contamination. Insert: Magnified area BS shown in BSE mode.