Grant-in-Aid for Scientific Research (C)
|Allocation Type||Single-year Grants|
|Research Institution||iwaki Meisei University|
YOKOSUKA Masaru(2003) Iwaki Meisei University, College of Science and Engineering, Prof., 理工学部, 教授 (70099985)
吉田 育之 いわき明星大, 理工学部, 教授 (30200976)
YOSHIDA Ikushi Iwaki Meisei University, College of Science and Engineering, Research assistant, 理工学部, 教授 (30200976)
SAKURAI Masashi Iwaki Meisei University, College of Science and Engineering, Research assistant, 理工学部, 研究助手 (50326790)
ONO Takafumi Iwaki Meisei University, College of Science and Engineering, Prof., 理工学部, 研究助手 (30306097)
横須賀 勝 いわき明星大学, 理工学部, 教授 (70099985)
|Project Period (FY)
2002 – 2003
Completed(Fiscal Year 2003)
|Budget Amount *help
¥1,700,000 (Direct Cost : ¥1,700,000)
Fiscal Year 2003 : ¥600,000 (Direct Cost : ¥600,000)
Fiscal Year 2002 : ¥1,100,000 (Direct Cost : ¥1,100,000)
|Keywords||piezoelectricity / ferroelectrics / composite / damping / internal friction / molecular alloying / barium titanate / lead titanate / ダンピング / PbTiO_3 / BaTiO_3|
1.Internal friction of piezoelectric ferroelectric ceramics.
Three kinds of ceramic specimens, BT[BaTiO_3], PZT[Pb(Zr_<0.52>Ti_<0.48>)O_3], PNN-PT-PZ50/33/17, were prepared for torsion pendulum type internal friction measurement. It is known that BT makes phase transitions successively as triclinic→orthorhombic→a tetragonal→cubic(paraelectric). Sharp internal friction peaks were observed corresponding to each phase transition. Rigidity minima were also observed accompanying the phase transitions.
2.Preparation of composites of copper and piezoelectric ferroelectric particles.
(1)Melting in a high frequency induction furnace : It was found that the wettability of molten copper against ceramics is quite insufficient, therefore ceramic particles were separated out from the metal.
(2)Silver plating of ceramic chips before melting together with copper in order to enhance the wettability. Plating was found not firm enough, and was easily peeled off by heating.
(3)Ceramic particles and copper particles were mixed well and pressed into a copper tube, and rolling with intermediate annealing was repeated to a final size of 2mm in diameter.
(4)Mechanical alloying : powders of BT (1μm diameter) and copper(100 4μm diameter) were mixed and pressed by MA method, and then cold-pressed, sintered and sliced to a size of 2x2x45mm^3
Methods (3) and (4) were successful.
3.Internal friction of Cu-ferroelectrics composites
Cu-PT composites prepared by the method (3) showed 3 to 5 times higher damping than copper. The internal friction of Cu increases with increasing temperature due to the gram boundary slip, while that of the composite remains constant up to 500K, and then begins to increase. Cu-Pt composite prepared by MA method also showed an enhanced damping, and peaks were observed at phase transition temperatures.