Ponson Laurent, Auradou Harold, Vié Philippe, Hulin Jean-Pierre
Laboratoire Fluides, Automatique et Systèmes Thermiques, UMR 7608, Universités Pierre et Marie Curie-Paris 6 et Paris-Sud, Bâtiment 502, Campus Paris Sud, 91405 Orsay Cedex, France.
Phys Rev Lett. 2006 Sep 22;97(12):125501. doi: 10.1103/PhysRevLett.97.125501. Epub 2006 Sep 18.
The geometry of postmortem rough fracture surfaces of porous glass ceramics made of sintered glass beads is shown experimentally to be self-affine with an exponent zeta=0.40+/-0.04, remarkably lower than the "universal" value zeta=0.8 frequently measured for many materials. This low value of zeta is similar to that found for sandstone samples of similar microstructure and is also practically independent on the porosity phi in the range investigated (3%< or =phi< or =26%) as well as on the bead diameter d and of the crack growth velocity. In contrast, the roughness amplitude normalized by d increases linearly with phi while it is still independent, within experimental error, of d and of the crack propagation velocity. An interpretation of this variation is suggested in terms of a transition from transgranular to intergranular fracture propagation with no influence, however, on the exponent zeta.
实验表明，由烧结玻璃珠制成的多孔玻璃陶瓷的死后粗糙断裂表面的几何形状是自仿射的，指数ζ = 0.40±0.04，明显低于许多材料经常测量的“通用”值ζ = 0.8。ζ的这个低值与具有相似微观结构的砂岩样品的值相似，并且实际上也与所研究范围内的孔隙率φ（3%≤φ≤26%）、珠子直径d以及裂纹扩展速度无关。相比之下，以d归一化的粗糙度幅度随φ线性增加，而在实验误差范围内，它仍然与d和裂纹扩展速度无关。根据从穿晶断裂扩展到沿晶断裂扩展的转变对这种变化进行了解释，然而，这对指数ζ没有影响。
