This paper reports on the post-processing disintegration of melt-infiltrated aluminum-carbon nanotube (Al-CNT) composites. The paper shows that un-optimized processing conditions can lead to the deterioration of the consolidated composite into micro-scale powder over time. Extensive characterization of the disintegration process over unprecedented post-processing times of similar to 2.5 years was conducted. The effect of post-processing time on the morphological and phase changes is discussed. The paper points to the importance and need to evaluate the long-term properties of Al-CNT composites.