Fractal dimension of pore-structure of porous metal materials made by stainless steel powder

► Fractal dimension decreases continuously as magnification increasing. ► Optimal magnification of pore-structure ranges from × 200 to × 500. ► Fractal dimension increases gradually with the porosity increasing. ► Relationship between fractal dimension and magnification accords with D=a0exp−xa1+a2. ► Relationship between fractal dimension and porosity satisfies D=k2−k1−k21+expθ−k0k3.