The fatigue crack growth resistance in the TL orientation is inferior to that in the LT orientation for both alloys and composites in T4 and T6 tempers.

• 在等力量疲劳裂缝生长实验方面，不论是T4或T6时效处理，LT型态之试片比起TL型态有较佳之抗疲劳生长能力。