• 제목/요약/키워드: Zr-based amorphous alloy

검색결과 41건 처리시간 0.022초

Cu-Zr-Ti-Ni-Pd계 비정질 벌크합금의 형성과 성질 (Cu-based Bulk Amorphous Alloys in the Cu-Zr-Ti-Ni-Pd System)

  • 김성규;배차헌
    • 한국주조공학회지
    • /
    • 제22권6호
    • /
    • pp.304-308
    • /
    • 2002
  • The new Cu-Zr-Ti-Ni-Pd amorphous alloy system has been introduced and manufactured using melt-spinning and Cu-mold die casting methods. Amorphous formability, the supercooled liquid region before crystallization and mechanical properties of the alloys were examined. The reduced glass transition temperature(Trg = Tg/Tm) and the supercooled liquid region(${\Delta}$Tx = Tx-Tg) of $Cu_{49}Zr_{30}Ti_{10}Ni_5Pb_6$ alloy were 0.620 and 57 K respectively. $Cu_{49}Zr_{30}Ti_{10}Ni_5Pb_6$ amorphous alloy was produced in the rod shape with 2mm diameter using the Cu-mold die casting. The hardness value of the amorphous bulk alloy was 432 DPN.

Pd 코팅된 Zr기 비정질 합금의 수소취성 및 표면특성 (Hydrogen Embrittlement and Surface Properties of Pd-coated Zr-based Amorphous Alloys)

  • 석송;이덕영;김기배
    • 한국수소및신에너지학회논문집
    • /
    • 제18권2호
    • /
    • pp.182-188
    • /
    • 2007
  • [ $Zr_{50}-Ni_{27}-Nb_{18}-Co_5$ ] amorphous alloys ribbon was prepared by a single-roller melt-spinning technique. In order to improve the hydrogen kinetics Pd-coating were carried out on each side of the amorphous ribbon. Pd prevents oxidation of Zr and catalyses the dissociation of molecular hydrogen to atomic hydrogen. In this work, the hydrogen embrittlement and surface properties on Zr-based amorphous alloys were investigated. The Zr-based amorphous alloys were characterized by X-ray diffractometry(XRD) and differential scanning calorimetry(DSC). The morphology of surface and roughness was observed by using scanning electron microscopy(SEM) and atomic force microscopy (AFM). A lattice parameter of both Pd and Zr-based amorphous alloy was increased after hydrogen permeation at 473 K. After hydrogen permeation at 473 K, some cracks were observed on the surface of Pd, which was the cause for the hydrogen embrittlement. The crystallization temperature of Zr-based amorphous alloy was decreased due to the permeated hydrogen.

Ni기 비정질 벌크합금의 제조와 기계적 성질 (Fabrication and Mechanical Properties of Ni-based Amorphous Bulk Alloys)

  • 김성규
    • 한국주조공학회지
    • /
    • 제22권6호
    • /
    • pp.288-292
    • /
    • 2002
  • Ni-base amorphous alloys were manufactured using melt-spinning and Cu-mold die casting methods. Amorphous formability, the supercooled liquid region before crystallization and mechanical properties were examined. The reduced glass transition temperature and the supercooled liquid region of $Ni_{51} Nb_{20} Zr_9 Ti_9 Co_8 Cu_3$alloy were 0.621 and 46 K respectively. $Ni_{51} Nb_{20} Zr_9 Ti_9 Co_8 Cu_3$ alloy was produced in the rod shape 3mm diameter using the Cu-mold die casting. Hardness, compression strength, elongation and elastic modulus of the alloy were 850 DPN, 2.75 GPa, 1.8% and 150 GPa respectively. Moreover, compression strength of 2.75 GPa was the highest value in the amorphous bulk alloy produced up to now.

벌크형 비정질 Zr계 합금의 결정화 열처리에 따른 동적변형 거동 (Dynamic Deformation Behavior of Zr-Based Bulk Amorphous Alloy after Annealing Treatments)

  • 장재준;이병주;황진일;박익민;조경목;조영래
    • 한국재료학회지
    • /
    • 제14권3호
    • /
    • pp.181-185
    • /
    • 2004
  • The mechanical properties of a bulk amorphous alloy ($Zr_{41.2}$ $Ti_{13.8}$ /$Cu_{10}$ $Ni_{10}$ $Be_{22.5}$ /at.%) before and after an annealing treatment were investigated. For the bulk amorphous alloy, the compressive strength was about 2.0 GPa, irrespective of the strain rates in the range of $10^{-4}$ to $10^3$$ sec^{-1}$ . Fine-sized nanocrystalline particles (10~100 nm) were precipitated homogeneously in the bulk amorphous matrix after the annealing treatments. Compared to the bulk amorphous materials, these composite materials, composed of the nanocrystalline phases and a bulk amorphous matrix had much different mechanical properties. The strength and strain of coposite materials measured by a compressive test showed a peak-maximum values at 7 vol.% of the nanocrystalline phases. The values in higher volume fraction of the crystalline phases in the amorphous matrix were decreased, as measured by both quasi-static and high strain rate. The decrease in fracture strength is due to presence of the dispersed large-crystalline phases in the amorphous matrix.

Zr기 비정질 합금 다이캐스팅 주조품의 부식 특성에 미치는 블라스팅 처리의 영향 (The Effect of Blasting Treatment on the Corrosion Characteristics in the Zr-based Amorphous Alloy Die Castings)

  • 이병철;김성규;박봉규;배차헌;박흥일
    • 한국주조공학회지
    • /
    • 제34권2호
    • /
    • pp.60-66
    • /
    • 2014
  • A Zr-based amorphous alloy specimen was produced by vacuum die casting process. The salt spray test was carried out using the specimens in the as-cast, $Al_2O_3$ and $ZrO_2$ particle blasted state. Using these specimens, the SEM-EDX and XRD analyses, DSC measurement and bending strength test were conducted. After the salt spray test, the specimens were not experienced phase change and thermal characteristics of the alloys were remained unchanged. In the as-cast specimen, corrosion products were not observed. However, in the $Al_2O_3$ particle blasted specimen, pitting corrosion occurred and the detected corrosion products were $ZrCl_2$ and $NaZrO_3$. Due to the salt spray test, bending strength of the $Al_2O_3$ blasted specimens showed about 100 MPa lower strength than the other specimens. The bending fracture surface was vein pattern which was shown typically in the amorphous alloys.

Zr-based 비정질 합금의 비정질 특성에 미치는 Sn의 영향 (The Effect of Sn on the Glass Formation Ability of the Zr-based Amorphous Alloy)

  • 이병철;박흥일;박봉규;김성규
    • 한국주조공학회지
    • /
    • 제34권2호
    • /
    • pp.49-53
    • /
    • 2014
  • In commercial Zr-Nb-Cu-Ni-Al amorphous alloys, expensive element, Zr, was substituted to Sn which was cheaper one, and then, glass forming ability, compressive strength and hardness of them were estimated. Even though the Sn was added up to 1.5%, resulting phase was not changed to the crystalline form. It was confirmed by X-ray diffraction and thermal analyses. In the X-ray profiles, there were no peaks for crystalline phases and typical halo pattern for amorphous phase was appeared at the diffraction angle of $35^{\circ}{\sim}45^{\circ}$. Thermal analyses also showed that the Sn modified alloys were corresponded to the amorphous standards where ${\delta}T$(= Tx - Tg) and Trg(= Tg/Tm) affecting to the amorphous forming ability were more than 50K and 0.60 respectively. Compressive strengths were 1.77 GPa, 1.63 GPa, 1.65 GPa and 1.77 GPa for 0%Sn, 0.5%Sn, 1.0%Sn and 1.5%Sn respectively. Hardnesses of the Sn modified alloys were decreased from 752 Hv to 702 Hv in 1.0%Sn and recovered to 746 Hv in 1.5%Sn.

플럭스처리에 의한 벌크비정질합금 스크랩의 비정질형성능 (Glass Forming Ability of Bulk Amorphous Alloy Scrap by Fluxing)

  • 강복현;김기영
    • 한국주조공학회지
    • /
    • 제30권3호
    • /
    • pp.94-99
    • /
    • 2010
  • When the returned scrap of bulk amorphous alloy is remelted, impurities such as oxides and intermetallic compounds increase. Glass forming ability of its scrap is deteriorated remarkably. Melt fluxing technique is introduced to enhance the glass forming ability during melting and freezing of bulk amorphous alloys. Cu and Zr based alloys are chosen. Small pieces of these alloy scraps and $B_2O_3$ flux are put together in a quartz tube. Cyclic heating and cooling are done by induction heating and water quenching or air cooling. Melting fluxing was effective for both Cu-based and Zr-based alloy, and their glass forming abilities were improved with increasing the number of fluxing.

PAS법을 이용한 Ni기 비정질 분말의 소결 (Sintering of Ni-Based Amorphous Alloy Powders by Plasma Activated Sintering Process)

  • 구자민;신기삼;김윤배;배종수;허성강
    • 한국재료학회지
    • /
    • 제15권12호
    • /
    • pp.765-772
    • /
    • 2005
  • PAS(Plasma Activated Sintering) process was tried to apply for the fabrication of BMG(Bulk Metallic Glasses) of $Ni_{57}Zr_{20}Ti_{18}Si_5}\;and\;Ni_{57}Zr_{20}Ti_{18}Si_3Sn_2$ from the as-atomized amorphous powder. Compressive strength for the BMG(bulk Metallic Glasses) of $Ni_{57}Zr_{20}Ti_{18}Si_5$ were lower than those of BMG rods produced by warm extrusion ,or copper mold casting method. Microstructural examination by optical microcope, SEM ana EDS showed that oxidation had occurred during PASintering. In order to prevent the powder from the oxidation during PASintering, Ni coating for $Ni_{57}Zr_{20}Ti_{18}Si_5$ amorphous powder by electroless-plating method was performed. Microstructural examination for Ni coated layers after PASintering indicated that the Ni coating had been so effective to prevent powder from oxidation during PASintering. Sintering behaviors of $Ni_{57}Zr_{20}Ti_{18}Si_3Sn_2$ represent the same as those of $Ni_{57}Zr_{20}Ti_{18}Si_5$.

Zr 기지 비정질 합금 스크랩의 비정질 형성능 및 기계적 성질에 미치는 재용해 횟수와 탄소 함량의 영향 (The Effect of Remelting Cycles and Its Carbon Content on the Glass Forming Ability and Mechanical Properties of the Zr-based Amorphous Alloy Return Scrap)

  • 이병철;김성규;박봉규;박흥일;박화순
    • 한국주조공학회지
    • /
    • 제34권3호
    • /
    • pp.94-99
    • /
    • 2014
  • A commercially used Zr-based amorphous alloy was recycled and the effects of introducing carbon during recycling on the glass forming ability and mechanical properties of the alloy were investigated. The initial carbon content used in this study was 229ppm. The carbon content was gradually increased as the number of recycling iterations was increased and after the $4^{th}$ recycling it rapidly increased. As return scrap was recycled, polygonal particles precipitated, and they were identified as ZrC. The amount of the precipitates also increased with recycling. Tg, Tx and ${\Delta}T$ of the base alloy were 615 K, 696 K and 81 Kr respectively and they changed to 634 K, 706 K and 72 K after the $10^{th}$ recycling. The decrease of the ${\Delta}T$ value indicates deterioration of the glass forming ability. Hardness was not changed during three iterations of recycling but after the $4^{th}$ recycling it significantly increased. This is ascribed to an increase of amount of the hard particles, namely ZrC.

Nanocrystallization of Cu-Based Bulk Glassy Alloys upon Annealing

  • Pengjun, Cao;Dong, Jiling;Haidong, Wu;Peigeng, Fan;Anruo, Zhou
    • Applied Microscopy
    • /
    • 제46권1호
    • /
    • pp.32-36
    • /
    • 2016
  • The Cu-based bulk glassy alloys in Cu-Zr-Ti-Ni systems were prepared by means of copper mold casting. The Cu-based bulk glassy alloys samples were tested by X-ray diffractomer (XRD), differential scanning calorimeter, scanning electron microscopy (SEM), Instron testing machine and Vickers hardness instruments. The result indicated that the prepared Cu-Zr-Ti-Ni alloys were bulk glassy alloys. The temperature interval of supercooled liquid region (${\Delta}T_x$) was about 45.48 to 70.98 K for the Cu-Zr-Ti-Ni alloy. The Vickers hardness was up to 565 HV for the $Cu_{50}Zr_{25}Ti_{15}Ni_{10}$ bulk glassy alloy. The $Cu_{50}Zr_{25}Ti_{15}Ni_{10}$ bulk glassy alloys were annealed in order to obtain nanocrystals. The results showed that the Vickers hardness was raise up to 630 HV from 565 HV. As shown in XRD results, the amorphous alloys changed to nanocrystals, which were $Cu_8Zr_3$, $Cu_3Ti_2$ and CuZr, improved the hardness. The SEM analysis showed that the compression fractured morphology of amorphous alloys was brittle fracture, and the fracture morphology after annealing was ductile fracture. This proved that annealing of amorphous to nanocrystals can improve the plasticity and toughness of amorphous alloys.