Typical Vickers indentation on a 4 vol% carbon nanotube (CNT) reinforced ZrB2 ceramic composite s...
Typical Vickers indentation on a 4 vol% carbon nanotube (CNT) reinforced ZrB2 ceramic composite shows cracks emanating from the indentation corners (see figure). The indentation was obtained using load of 1000 g and holding time of 15 s (Vickers Hardness tester). Fracture toughness and Hardness of material are given by expressions: 1/2 0.016(5) H/2 1.854P where E is Young's Modulus of the composite (GPa); H is Vickers Hardness (GPa); P is applied load (N); c is diagonal crack length emanating from corner (m); and L is average length of indentation diagonal. Moduli of elasticity for ZrB2 ceramic and carbon nanotubes are 500 GPa and TPa, respectively. Assuming the composite modulus to be the average of moduli predicted by iso-strain and iso-stress analyses, calculate fracture toughness mag WD det spotHV 2 120x 9.9 mm ETD 25 10.00 kv 12: 10:51 PM /20/201
Typical Vickers indentation on a 4 vol% carbon nanotube (CNT) reinforced ZrB2 ceramic composite shows cracks emanating from the indentation corners (see figure). The indentation was obtained using load of 1000 g and holding time of 15 s (Vickers Hardness tester). Fracture toughness and Hardness of material are given by expressions: 1/2 0.016(5) H/2 1.854P where E is Young's Modulus of the composite (GPa); H is Vickers Hardness (GPa); P is applied load (N); c is diagonal crack length emanating from corner (m); and L is average length of indentation diagonal. Moduli of elasticity for ZrB2 ceramic and carbon nanotubes are 500 GPa and TPa, respectively. Assuming the composite modulus to be the average of moduli predicted by iso-strain and iso-stress analyses, calculate fracture toughness mag WD det spotHV 2 120x 9.9 mm ETD 25 10.00 kv 12: 10:51 PM /20/201