• Title, Summary, Keyword: Zr/Ti ratio

Search Result 184, Processing Time 0.049 seconds

Piezoelectric characteristics of Low temperature sintering ceramics according to Zr/Ti ratio (저온소결 PSN-PZT 세라믹스의 Zr/Ti 비에 따른 압전특성)

  • Woo, Won-Hee;Ryu, Sung-Lim;Yoo, Ju-Hyun;Oh, Dong-Un;Hong, Jae-Il;Lee, Sang-Ho
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • /
    • pp.656-659
    • /
    • 2003
  • In this study, in order to develop the low temperature sintering ceramics for multilayer piezoelectric transformer, dielectric and piezoelectric properties of PSN-PZT ceramics were investigated according to Zr/Ti ratio. As Zr/Ti ratio is increased, coupling factor(kp) and dielectric constant were increased and then decreased after the ratio of Zr/Ti=50/50. And also, mechanical quality factor were decreased and then increased after the ratio of Zr/Ti=50/50.

  • PDF

Piezoelectric Characteristics of Low-temperature Sintered PSN-PZT Ceramics as a Function of Zr/Ti Ratio (저온소결한 PSN-PZT 세라믹스의 Zr/Ti 비에 따른 압전특성)

  • 류주현;우원희;오동언;정영호;정광현;류성림
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.16 no.12S
    • /
    • pp.1195-1199
    • /
    • 2003
  • In this study, in order to develop the low temperature sintering ceramics for multilayer piezoelectric transformer, dielectric and piezoelectric properties of PSN-PZT[0.91Pb(Sb$\sub$1/2/Nb$\sub$1/2/)$\sub$0.03/(Zr$\sub$0.495/Ti$\sub$0.505/)$\sub$0.97/O$_3$-0.04Pb(Ni$\sub$1/2/W$\sub$1/2/)O$_3$+0.05BiFeO$_3$+0.3wt%MnO$_2$+0.6wt%CuO〕 ceramics were investigated according to Zr/Ti ratio. As Zr/Ti ratio is increased, electromechanical coupling factor(k$\sub$p/) and dielectric constant increased and then decreased after the ratio of Zr/Ti=50/50. Also, mechanical qualify factor(Q$\sub$m/) decreased and then increased after the ratio of Zr/Ti=50/50.

Grindability of Cast Ti-X%Zr(X=10,20,40) Alloys for Dental Applications (치과주조용 Ti-X%Zr(X=10,20,40)합금의 연삭성)

  • Jung, Jong-Hyun;Noh, Hyeong-Rok
    • Journal of Technologic Dentistry
    • /
    • v.33 no.4
    • /
    • pp.263-270
    • /
    • 2011
  • Purpose: The grindability of binary Ti-X%Zr(X=10,20,40) alloys in order to develop a Ti alloy with better machinability than unalloyed titanium has been evaluated. Methods: Experimental Ti-Zr alloys were made in an argon-arc melting furnace. Slabs of experimental alloys were ground using a SiC abrasive wheel on an electric handpiece at circumferential speeds(12000,18000,25000 or 30000rpm) by applying a force(200gr). Grinding rate was evaluated by measuring the amount of metal volume removed after grinding for 1 minute and the volume ratio of metal removed compared to the wheel material lost, which was calculated from the diameter loss (grinding ratio). Experimental datas were compared to those for cp Ti(commercially pure titanium) and Ti-6%Al-4%V alloy were used controls. Results: It was observed that the grindability of Ti-Zr alloys increased with an increase in the Zr concentration. More, they are higher than cp Ti, particularly the Ti-20%Zr alloy exhibited the highest grindability at all circumferential speeds. There was significant difference in the grinding rate and grinding ratio between Ti-20%Zr alloy and cp Ti at any speed(p<0.05). Conclusion: By alloying with Zr, the Ti exhibited better grindability at all circumferential speeds. the Ti-20%Zr alloy has a great potential for use as a dental machining alloy.

Grindability of Ti-10%Zr-X%Cr(X=0,1,3) Alloys for Dental Applications (치과용 Ti-10%Zr-X%Cr(X=0,1,3)합금의 연삭성)

  • Jung, Jong-Hyun;Shin, Jae-Woo
    • Journal of Technologic Dentistry
    • /
    • v.35 no.4
    • /
    • pp.295-302
    • /
    • 2013
  • Purpose: The grindability of Ti-10%Zr-X%Cr(X=0,1,3) alloys in order to develop Ti alloys for dental applications with better machinability than unalloyed titanium has been evaluated. Methods: Experimental Ti-10%Zr-X%Cr(X=0,1,3) alloys were made in an argon-arc melting furnace. Slabs of experimental alloys were ground using a SiC abrasive wheel on an electric handpiece at one of the four rotational speeds of the wheel (12000, 18000, 25000 or 30000rpm) by applying a force(100gf). Grindability was evaluated by measuring the amount of metal volume removed per minute(grinding rate) and the volume ratio of metal removed compared to the wheel material lost, which was calculated from the diameter loss (grinding ratio). Experimental datas were compared the results with those of cp-Ti(commercially pure titanium) Results: It was observed that the grindability of Ti-10%Zr-X%Cr(X=0,1,3) alloys increased with an increase in the Cr concentration. More, they are higher than cp-Ti, particularly the Ti-10%Zr-3%Cr alloy exhibited the highest grindability at all rotational speeds except 12000rpm. There was significant difference in the grinding rate and grinding ratio between Ti-10%Zr-3%Cr alloy and cp-Ti at all rotational speeds(p<0.05). Conclusion: The Ti-10%Zr-3%Cr alloy exhibited better grindability at high rotational speeds, great potential for use as a dental machining alloy.

Dielectric Properties and Microstructure of Modified $CaZrO_3$ for Application of Ni-MLCC with NPO Temperature Characteristics (NPO 온도특성의 Ni-MLCC 응용을 위한 CaZrO3의 유전특성 및 미세구조)

  • Chun, Myoung-Pyo;Myoung, Seong-Jae;Han, Ik-Hyun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • /
    • pp.30-32
    • /
    • 2005
  • The effects of mole ratio and Ti-ion on the dielectric properties and microstructure of modified $CaZrO_3$ composition such as $(Ca_{0.7}Sr_{0.3})_m(Ti_yZr_{1-y})O_3$ were investigated. Ti ions substituted on Zr-sites in these modified $CaZrO_3$ composition strongly affect the sintering density and microstructure of the fired ceramic body. With increasing the amount of Ti substituted on Zr-sites, the sintered density rapidly increased and the dense microstructures were obtained for the compositions having mole ratio of 1.01, whereas the sintered density and microstructures are nearly constant with the content of Ti-ion for the compositions having mole ratio of 0.99. With increasing the content of Ti ion, the curve of TCC (temperature coefficient of capacitance) as a function of temperature rotated clockwise and satisfied the COG characteristics for both of compositions with mole ratio of 0.99 and 1.01. The content of Ti ion seems to be more effective than mole with respect to the controlling of firing and TCC.

  • PDF

The Effect of Ti to Zr Addition Ratio on the Thermal Stability of Mechanically Alloyed Al-8wt.% (Ti+Zr) Alloy (기계적합금화한 Al-8wt.%(Ti+Zr)합금의 열적안정성에 미치는 Ti : Zr첨가비의 영향)

  • Kim, Jun-Gi;Kim, Seon-Jin
    • Korean Journal of Materials Research
    • /
    • v.5 no.8
    • /
    • pp.945-952
    • /
    • 1995
  • The effect of Zr content on the thermal stability of mechanically alloyed Al-8wt.% (Ti+Zr) alloys was investigated. As the Zr to Ti addition ratio increased the decrease of hardness due to the long time exposure at high temperature reduced so that the thermal stability of the alloy was improved. From the TEM work it was found that the coarsening of precipitates was responsible for the decrease of hardness and the coarsening of precipitates could be suppressed by the addition of Zr, XRD, SAD and EDS analyses confirmed that these precipitates were consisted of DO$\sub$22/, and DO$\sub$23/ type Al$_3$(Ti+Zr) ternary in termetallic compounds. Especially for the DO$\sub$23/ Al$_3$(Ti+Zr), the lattice parameter changed toward the smaller lattice mismatch between the precipitate and Al matrix as the Zr content increased. Therefore, it was considered that the improvement of thermal stability of Al-8wt.% (Ti+Zr) alloys was due to the formation of the ternary Al$_3$( Ti + Zr) intermetallic compounds.

  • PDF

Magnetoresistance and Structural Properties of the Magnetic Tunnel Junction with Ternary Oxide Barrier (삼원계 산화 절연층을 가진 자기터널접합의 자기·구조적 특성에 관한 연구)

  • Park, Sung-Min;Lee, Seong-Rae
    • Journal of the Korean Magnetics Society
    • /
    • v.15 no.4
    • /
    • pp.231-235
    • /
    • 2005
  • We studied the microstructural evolution of ZrTM-Al (TM=Nb and Ti) alloy films, MR and electrical properties of the MTJ with $ZrTM-AlO_x$ barrier as a function of Zr/TM ratio. We observed that the ternary-oxide barrier reduced the TMR ratio due mainly to the structural defects such as the surface roughness. The change in TMR ratio and $V_h$ with Zr/TM ratio exactly corresponds to the systematic changes in the microstructural variation. Although the MTJ with ternary oxide reduced the TMR and the electrical stabilities, the junction resistances decreased as the Ti and Nb concentration increased due to the band-gap reduction caused by the formation of extra bands

Effects of $Ba(La_{1/2}Nb_{1/2})O_3$ content and Zr/Ti composition ratio on electrooptic properties of the $Ba(La_{1/2}Nb_{1/2})O_3-Pb(Zr, Ti)O_3$ ceramics ($Ba(La_{1/2}Nb_{1/2})O_3$의 고용량과 Zr/Ti 조성비가 $Ba(La_{1/2}Nb_{1/2})O_3-Pb(Zr, Ti)O_3$ 세라믹의 전기광학 특성에 미치는 영향)

  • 류기원;이성갑;배선기;이영희
    • The Transactions of the Korean Institute of Electrical Engineers
    • /
    • v.44 no.5
    • /
    • pp.644-648
    • /
    • 1995
  • Transparent xBa(La$_{1}$2/Nb$_{1}$2/)O$_{3}$-(1-x)Pb(Zr, Ti)O$_{3}$ (x=8.5, 9.0[mol.%], Zr/Ti=70/30~40/60) ceramics were fabricated by the two-stage sintering method, the electrooptic properties were investigated with Ba(La$_{1}$2/Nb$_{1}$2/)O$_{3}$ content and Zr/Ti composition ratio. Decreasing the Zr/Ti ratio, the electrooptic property was changed from a quadratic electrooptic effect to a linear electrooptic effcet. In the BLN-PZT 9.0/50/50 specimen having the tetragonal structure, the linear electrooptic coefficient had the highest value of 6.01*10$^{-10}$ [m/V] and in the BLN-PZT 9.0/55/45 specimen which located near the MPB region, the quadratic electrooptic coefficient had the highest value of 10.53*10$^{-16}$ [m$^{2}$/V$^{2}$].

  • PDF

Electrical properties and microstructure of microwave dielectric ceramics (Ca0.7Sr0.3)m(TiyZr1-y)O3 (고주파 유전체 세라믹 (Ca0.7Sr0.3)m(TiyZr1-y)O3의 전기적 특성 및 미세구조)

  • Chun, Myoung-Pyo;Park, Myoung-Sung;Kang, Kyung-Min;Nam, Joong-Hee;Cho, Jeong-Ho;Kim, Byung-Ik
    • Journal of the Korean Crystal Growth and Crystal Technology
    • /
    • v.20 no.1
    • /
    • pp.21-24
    • /
    • 2010
  • The effects of mole ratio(A/B) m and Ti-ion on the dielectric properties and microstructure of the microwave dielectric ceramics $(Ca_{0.7}Sr_{0.3})_m(Ti_yZr_{1-y})O_3$ were investigated. Ti ions substituted on Zr-sites in these modified $CaZrO_3$ composition strongly affect the sintering density and microstructure of the fired ceramic body. With increasing the amount of Ti substituted on Zr-sites, the sintered density rapidly increased and the dense microstructure was obtained for the compositions having mole ratio of 1.01, whereas the sintered density and microstructure are nearly constant with the content of Ti-ion for the compositions having mole ratio of 0.99. With increasing the content of Ti ion, the curve of TCC (Temperature Coefficient of Capacitance) as a function of temperature rotated clockwise and satisfied the COG characteristics for both of compositions with mole ratio of 0.99 and 1.01. The content of Ti ion seems to be more effective than mole with respect to the controlling of firing and TCC.

Effects of PSN Substitution on the Microstructural and Piezoelectric Characteristics of PNN-PZT Ceramics (PSN 치환이 PNN-PZT 세라믹스의 미세구조 및 압전 특성에 미치는 영향)

  • 윤광희;민석규;류주현;박창엽;정희승
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.14 no.5
    • /
    • pp.356-361
    • /
    • 2001
  • The structureal, dielectric and piezoelectric properties of Pb[(Sb$\_$1/2/Nb$\_$1/2/)$\_$x/-(Ni$\_$1/3/Nb$\_$2/3/)$\_$0.15-x/-(Zr$\_$y/Ti$\_$1-y/)$\_$0.85/]O$_3$(x=0∼0.05, y=0.47∼0.52) ceramics were investigated with the substitution of Pb(Sb$\_$1/2/Nb$\_$1/2/)O$_3$(abbreviated PSN) and the Zr/Ti ratio. At Zr/Ti ratio of 50/50, tetragonality was decreased and grain size abruptly decreased with the increase of PSN substitution. Curie temperature was decreased and dielectric constant increased with the substitution of PSN. The coercive field increased and remnant polarization decreased with the substitution of PSN. Electromechanical coupling factor(k$\_$p/) showed the highest value of 0.622 at 1mol% PSN, but mechanical quality factor(Q$\_$m/) showed the minimum value at that composition. Dielectric constant and electromechanical coupling factor with the Zr/Ti ratio showed maximum values at Zr/Ti ratio of 50/50 and mechanical quality factor showed minimum values near the Zr/Ti ratio of 50/50.

  • PDF