Tatsuya Sugihara 교수

In cutting of aluminum alloys, one of the most serious problems is chip adhesion to cutting tool surface, leading to tool breakage. To solve this problem, we used a surface engineering approach, namely, a highly functionalization of tool surfaces by textures to determine the role of textured surfaces in: (i) retaining cutting fluid and (ii) reducing actual contact area between the tool and chips. In this study, a DLC-coated cutting tool with nano/micro-textured surface using femto-second laser t

Nickel-based superalloys such as Inconel 718 provide several advantages, including a high-temperature strength and high corrosion resistance. Therefore the demand for such materials has rapidly increased, particularly in the aviation and gas turbine applications. On the other hand, they are known as one of the most difficult-to-cut materials due to their mechanical and chemical properties and the tool life is extremely short. Recently, Cubic-Boron-Nitride (CBN) has received a considerable attent

Dry machining of aluminum alloys is one of the most challenging machining operations because these materials severely adhere to the tool surface without the use of cutting fluids, leading to deterioration of the surface integrity of the workpiece and tool failure. In order to overcome this problem, we newly developed cutting tools with dimple-shaped textures having different dimensions and arrays, generated on the tool rake face by using a femtosecond laser. A series of experiments demonstrated

Nickel-based superalloys such as Inconel 718 are known as one of the most difficult-to-cut materials due to their mechanical and chemical properties and the tool life is extremely short. Recently, Cubic-Boron-Nitride (CBN) has received considerable attention as a material for cutting tools and has already established itself in many areas of machining. However, the performance of CBN tools is still insufficient in practical use, especially in the high speed machining of Inconel 718. To overcome t

Recently, PCBN cutting tools have received a great deal of attention as a material for cutting tools to achieve high performance machining of Inconel 718. In this study, turning and orthogonal cutting experiments on Inconel 718 employing two types of PCBN cutting tool were conducted in order to evaluate the tool life and identify the wear mechanisms, at a wide range of cutting speeds. The results of the experiments indicated that the tool life and wear behavior of the PCBN cutting tools signific

Adsorbed films often influence mechanical behavior of surfaces, leading to well-known mechanochemical phenomena such as liquid metal embrittlement and environment-assisted cracking. Here, we demonstrate a mechanochemical phenomenon wherein adsorbed long-chain organic monolayers disrupt large-strain plastic deformation in metals. Using high-speed in situ imaging and post facto analysis, we show that the monolayers induce a ductile-to-brittle transition. Sinuous flow, characteristic of ductile met

As titanium alloys such as Ti-6Al-4V provide several benefits, including high-temperature strength and high corrosion resistance, the demand for such materials has rapidly increased, particularly in the aircraft industries. On the other hand, they are known to be among the most difficult-to-cut materials due to their mechanical and chemical properties, which make tool life extremely short. In order to solve this problem, this paper proposes a new cutting method employing ultra-low-frequency (ULF