Observation of Crack Propagation Process in Aluminum Alloy Specimen Using Air-Servo Microfocus X-Ray CT System

User Benefits

- The Air-Servo Microfocus X-Ray CT System enables observation of crack propagation in three dimensions and over time. - Microfocus X-Ray CT system enables nondestructive observation of the interior of materials. - High-precision dynamic control is possible with the Servo Controller 4830.

Introduction

Many structural failures are caused by fatigue failure resulting from repeated loading. In fatigue failure, cracks initiate from microdefects in the material, internal voids, inclusions, and other features, and then propagate under repeated loading until final fracture occurs. To evaluate this sequence of processes, it is effective to observe defects and crack propagation nondestructively. Traditionally, crack observation has focused on visual inspection and microscopic observation, but these methods are limited to information near the surface. To sufficiently capture the three-dimensional shape and changes in cracks propagating inside a material, observation of the fractured specimen after failure has generally been used. In contrast, X-ray CT can nondestructively visualize internal defects and cracks in three dimensions, making it possible to evaluate in detail changes in crack morphology, including in the interior. Accordingly, using the “Air-Servo Microfocus X-Ray CT System,” which combines X-ray CT with a fatigue testing machine, repeated tests were performed in which loading was stopped at fixed cycle intervals and imaging was carried out. This article introduces the resulting process of crack initiation and propagation in the same specimen.

July 23, 2026 GMT