The University of Tokyo · 공학
Toru Kizaki 교수의 연구실은 고강도 세라믹 소재, 특히Y-安定화 테트라고날 zirconia 폴리크리스탈(Y-TZP)의 정밀가공 기술 개발에 초점을 맞추고 있습니다. 레이저 보조 가공(LAM)을 활용한 비다이아몬드 공구를 이용한 고효율, 고정밀 가공 기법과 함께, 기계 공구의 열변형 보정을 위한 고밀도 온도 측정 및 실시간 예측 기술을 동시에 개발하고 있습니다. 특히, 열적 변형에 기인하는 가공 오차를 최소화하기 위한 센서 최적 배치 및 열분포 모델링 기반의 실시간 제어 기술이 핵심 연구 주제입니다.
표시된 성과는 수집된 데이터 기준으로 산출되며, 일부 차이가 있을 수 있습니다.
Yttria-stabilized tetragonal zirconia polycrystal is a promising material for dental restoratives. The dominant manufacturing method of the dental restoratives comprises three steps. (1) Pressing (2) machining (3) final sintering. The method has disadvantages such as low geometrical accuracy and long process time in the final sintering stage. Thus, the direct machining method of the fully sintered Y-TZP which is difficult to machine is desired to realize an accurate, efficient and inexpensive fa
A novel temperature measuring system named LATSIS was proposed to realize a robust and accurate prediction of the thermal deformation of machining centers, even under external disturbances such as cutting fluid supply. LATSIS enables a drastic increase in the number of sensors employed for measuring the temperature of the machine tool. Thus, the entire temperature distribution can be obtained by interpolating the measured temperature 3-dimensionally without calculating the heat conduction. A set
To compensate for thermal errors in machine tools, strategic sensor placement and rapid error calculation are crucial. This study addresses these challenges using model order reduction. A transfer function matrix and a sensitivity function were defined to optimize the number and locations of sensors without physically attaching them to the machine tool. This methodology was validated through experiments on a 3-axis machining center. The number of sensors was reduced by 50 %, and the calculations
Temperature measurement of machine tools is very important for high precision machining as 70% of the machining error is due to thermal displacement. However, the temperature of the feed drive system has not been measured directly so far. In this study, we developed a wireless multi-point series temperature sensor system. The temperature distribution of the ball screw feed drive system was directly measured on a three-axis horizontal machining center. The results showed that the heat generated b
Yttria-stabilized tetragonal zirconia polycrystal is promising ceramic for artificial implants despite its difficult-to-cut feature. Thus, a machining method that enhances the process performance is required. We proposed UV laser-assisted machining of Y-TZP. In the process, the laser beam is utilized to ablate the material as well as to heat it. First, the optimal wavelength of the laser was determined by considering the fluence threshold for the ablation. In order to obtain the fluence threshol
Yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) is a promising material for dental restoratives. Although grinding or polishing with diamond tools is widely used to machine Y-TZP, the processing efficiency and cost of the process are problematic. In this study, we applied laser-assisted machining (LAM) to Y-TZP, in which non-diamond tools were used. Unlike LAM applied to other materials, decrease of the fracture toughness at elevated temperatures which is a unique feature of the Y-TZP
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