Identification of crack progression in filled rubber by micro X-ray CT-scan

Abstract Micro X-ray computed tomography (micro X-ray CT) is a technology that uses computer-processed X-rays to produce tomographic images (virtual ‘slices’) of specific areas of the scanned object, allowing the user to get the inside information without cutting. In comparison with traditional methods, such as optical or scanning electron (SEM) microscopy, Micro X-ray CT-scan has advantages in the study of rubber filler aggregation and crack developments for its continuous and no-break scanning. In this research, two types of filled styrene-butadiene rubber (SBR) reinforced with carbon black or silica were prepared and subjected to cyclic fatigue loads. Micro X-ray CT-scan tests were performed on both pristine (no fatigue) and fatigued samples. Filler aggregation as well as crack development and progression were investigated as a function of fatigue cycles by using micro X-ray CT-scan. Cracks were observed in directions both parallel (mode I) and perpendicular (mode II) to the applied uniaxial tensile fatigue loads.