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Tool alloys are wildly used as forming die materials because of their good hardenability by quenching and abrasive wear properties. Usually, die lubricant is used during forming process in order to avoid seizing and/or galling. Recently, however, it is known that the disposition of die lubricant as industrial waste is costly and detrimental to the environment, and dry forming process without lubricant is strongly required. Diamond-like carbon (DLC) film exhibits excellent properties such as high hardness, high coating adhesion, low defect density and chemical inertness. Furthermore, DLC film has very low coefficient of friction and high tribological properties [1], and is a strong candidate for the surface modification method of die materials for dry forming process. Recently, it is known that forming of complicated shape components induces the transition of localized stress field at the stress concentration part of dies from compression to tension during forming process. Therefore, it is very important to understand fracture mechanisms of DLC coated die materials under cyclic tension-compression loading patterns.