The contact-free evaluation of porosity of nickel foam by 3D X-ray tomography

The macrostructure of nickel foam with porosity of 20, 30, 45, and 60 ppi is investigated by X-ray tomography at voltage U = 300 kV, current I = 300 mA, and exposure time texp = 354 ms; the number of frames is 2500. It is established that the actual pore parameters deviate from theoretical ones. It is shown that, the higher porosity is, the more uniform pore size is. The X-ray tomography makes it possible to evaluate such characteristics as the wall thickness between the pores, which had not been taken into account previously. It is revealed that the size uniformity of the wall thickness lowers as the sample porosity increases. The results of the X-ray tomography make it possible to recommend it as the method for studying and monitoring foam materials, powders, and various sintered materials, and its data can be used to develop actual three-dimensional models.