Estimation of the Glass Forming Ability of the Fe-based Bulk Metallic Glass Fe68.8C7.0Si3.5B5.0P9.6Cr2.1Mo2.0Al2.0 that Contains Non-metallic Inclusions

Hongxiang Li,Zhaoping Lu,이승훈 대한금속·재료학회 2009 METALS AND MATERIALS International Vol.15 No.1

For the mass production of bulk metallic glasses, the use of industrial raw materials that contain certain amounts of inclusions is inevitable. The glass-forming ability of bulk metallic glasses, i.e., the critical cooling rate for glass formation upon solidification, is closely related to the nature of heterogeneous nucleation offered by inclusions during the solidification process. Significantly different effects of various types of inclusions on the glass forming ability of the alloy Fe68.8C7.0Si3.5B5.0P9.6Cr2.1Mo2.0Al2.0 are demonstrated in this study. The origins of the effects of different inclusions on the glass forming ability are analyzed through thermodynamic, crystallographic and classical heterogeneous nucleation kinetic theories. For the mass production of bulk metallic glasses, the use of industrial raw materials that contain certain amounts of inclusions is inevitable. The glass-forming ability of bulk metallic glasses, i.e., the critical cooling rate for glass formation upon solidification, is closely related to the nature of heterogeneous nucleation offered by inclusions during the solidification process. Significantly different effects of various types of inclusions on the glass forming ability of the alloy Fe68.8C7.0Si3.5B5.0P9.6Cr2.1Mo2.0Al2.0 are demonstrated in this study. The origins of the effects of different inclusions on the glass forming ability are analyzed through thermodynamic, crystallographic and classical heterogeneous nucleation kinetic theories.

방전플라즈마 소결법에 의한 비정질/비정질 복합재의 제조

이진규,Lee, Jin-Kyu 한국분말야금학회 2007 한국분말재료학회지 (KPMI) Vol.14 No.6

The Cu-based bulk metallic glass (BMG) composites containing Zr-based metallic glass phase have been consolidated by spark plasma sintering using the mixture of Cu-based and Zr-based metallic glass powders in their overlapped supercooled liquid region. The Zr-based metallic glass phases are well distributed homogeneously in the Cu-based metallic glass matrix after consolidation process. The successful consolidation of BMG composites with dual amorphous phases was corresponding to the sound viscous flow of the two kinds of metallic glass powders in their overlapped supercooled liquid region.

Development of Mo@?Ni@?Si@?B metallic glass with high thermal stability and H versus E ratios

Kim, J.,Kyeong, J.S.,Ham, M.H.,Minor, A.M.,Kim, D.H.,Park, E.S. Elsevier Ltd 2016 Materials & Design Vol.98 No.-

<P>We report a novel Mo-Ni-Si-B metallic glass which can be solidified into fully amorphous state by melt-spinning process, with high crystallization onset temperature of over 1100 K, extremely high Vickers hardness of 27.5 +/- 2.2 GPa and relatively low Young's modulus of 364.3 +/- 6.6 GPa. The dense cluster-packing model suggests that the addition of boron up to 10 at.% can occupy vacant cluster-interstices of (Mo, Ni)-Si cluster arrays, which results in a more efficiently dense-packed cluster structure, destabilizes the formation of nanocrystalline phases, and systematically increases the glass-forming ability (GFA) in Mo-Ni-Si-B alloys, The GFA parameters that do not directly rely on T-g, such as Delta T and epsilon parameter, show greater reliability to evaluate GFA for Mo-Ni-Si-B metallic glass exhibiting no clear T-g. The H/E and H-2/(2E) ratios of the newly developed Mo-Ni-Si-B metallic glass, which reflect wear resistance and resilience, exhibit the highest values among various hard ceramic materials as well as metallic glass-forming alloys developed up to now. These advantages of Mo-Ni-Si-B metallic glass can be used more widely to forma high temperature wear-resistant coating layer on various substrates. Furthermore, the same idea might be used to form a metallic glass-nitride nanocomposite coating layer by reactive deposition in N-2 ambient, with highly lubricative properly and high wear-resistance, especially at high temperature. (C) 2016 Elsevier Ltd. All rights reserved.</P>

Characteristics of volume change and heavy metal leaching in mortar specimens recycled heavyweight waste glass as fine aggregate

Choi, So Yeong,Choi, Yoon Suk,Yang, Eun Ik Elsevier 2018 Construction and Building Materials Vol.165 No.-

<P><B>Abstract</B></P> <P>Industrial waste, such as heavyweight waste glass, has become a global concern in terms of environmental safety and resource recycling. The reuse and recycling of heavyweight waste glass are necessary from the viewpoint of environmental protection. At the same time, concrete, three-quarters of which consists of aggregate, is one of the most widely used infrastructure materials, and it is being exhausted. The heavyweight waste glass being is considered as the most suitable substitute for aggregate due to its physical characteristics and chemical composition.</P> <P>In this study, to evaluate whether heavyweight waste glass could be as a concrete material, we carried out drying shrinkage, expansion by alkali-silica reaction (ASR) and heavy metal leaching of mortar. We found that when the heavyweight waste glass substitution ratio increased, the drying shrinkage decreased. Furthermore, the existing models predicted the experimental results, inversely. However, the expansion of ASR mortar gradually increased with an increase in the substitution ratio of heavyweight waste glass. When fly ash 20% or blast furnace slag 50% was mixed in mortar specimens, the ASR expansion could be controlled within the permitted limit of 0.1% at 14 days by the ASTM 1260 criteria. Moreover, the leached concentration of As, Cd, Cu and Hg from the mortar were detected below the criteria specified in drinking water regulatory levels, however, further investigation is needed to determine the leaching characteristics of Pb and Cr according to heavyweight waste glass substitution ratio in mortar specimens. Conclusively, the overall test results of this study have demonstrated that it may be feasible to utilize heavyweight waste glass as fine aggregate in mortar specimens.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The mortar specimens containing heavyweight waste glass were investigated. </LI> <LI> Drying shrinkage decreased with the increase of heavyweight waste glass. </LI> <LI> ASR expansion and heavy metal leaching quantities increased with the content of waste glass. </LI> <LI> The heavyweight waste glass substitution has a significant effect on the properties mortar specimens. </LI> <LI> Results are expected to provide a motivation to use heavyweight waste glass in mortar. </LI> </UL> </P>

스테인드글라스 예술에서의 채색창 대 장식창 논쟁 고찰

김호정 한국미술이론학회 2023 미술이론과 현장 Vol.- No.35

Today’s stained glass, with its diversity, differs from that of the Middle Ages that adorned medieval Gothic churches. This study questions why the term ‘stained glass’ is still commonly used even though what had originally been referred to as stained glass declined after the Middle Ages. It was not until the late 19th to early 20th centuries that the stained glass art was revived in Britain and the United States. This study examines two articles published in The Craftsman in March 1903: Frederick S. Lamb’s ‘The Painted Window’ and Charles H. Caffin’s ‘Decorated Window’. Lamb and Caffin sought to define the essence of stained glass and affirmed that the theories and ideals of the English Arts & Crafts Movement influenced the stained glass revival. Their debate is significant because, by trying to restore the essence and intrinsic characteristics of stained glass, they established stained glass as a creative art medium and provided the raison d’être of stained glass in today’s world. 중세 고딕 성당에서 시작된 스테인드글라스가 오늘날 중세와 비교해서 매우 다양하고다름에도 불구하고 여전히 ‘스테인드 글라스’라는 명칭으로 통용되는 이유를 규명해 보는 것이 본 연구의 목표다. 우리가 흔히 ‘스테인드글라스’라고 부르는 예술은 중세 이후 쇠퇴하였다가 19세기 후반부터 20세기 초 동안 영국과 미국에서 리바이벌되었다. 필자는 주요 연구대상인 잡지 『더 크래프츠맨』 1903년 3월호에 실린 프레더릭 S. 램(Frederick S. Lamb)의「채색창」과 찰스 H. 캐핀(Charles H. Caffin)의 「장식창」을 고찰하여, 그들이 공통적으로스테인드글라스의 본질을 무엇으로 정의할 것인가를 진지하게 고민했음을 밝히고, 그러한고민의 배경에 스테인드글라스 리바이벌을 이끈 영국 미술공예운동의 이론과 이상의 영향을확인하였다. 램과 캐핀의 논쟁은 스테인드글라스의 본질과 고유한 특성을 되살리려는 노력을 통해 창조적 예술 매체로서 스테인드글라스의 명맥이 현재까지 이어질 수 있었음을 알게해주었다는 점에서 의미가 있다.

기계적 합금화 공정에 의한 Hf계 비정질 분말의 미세변형거동 관찰

김송이,이아영,차은지,권도훈,홍성욱,이민우,김휘준,이민하,Kim, Song-Yi,Lee, A-Young,Cha, Eun-Ji,Kwon, Do-Hun,Hong, Sung-Uk,Lee, Min-Woo,Kim, Hwi-Jun,Lee, Min-Ha 한국분말야금학회 2018 한국분말재료학회지 (KPMI) Vol.25 No.3

In this study, we investigate the deformation behavior of $Hf_{44.5}Cu_{27}Ni_{13.5}Nb_5Al_{10}$ metallic glass powder under repeated compressive strain during mechanical milling. High-density (11.0 g/cc) Hf-based metallic glass powders are prepared using a gas atomization process. The relationship between the mechanical alloying time and microstructural change under phase transformation is evaluated for crystallization of the amorphous phase. Planetary mechanical milling is performed for 0, 40, or 90 h at 100 rpm. The amorphous structure of the Hf-based metallic glass powders during mechanical milling is analyzed using differential scanning calorimetry (DSC) and X-ray diffraction (XRD). Microstructural analysis of the Hf-based metallic glass powder deformed using mechanical milling reveals a layered structure with vein patterns at the fracture surface, which is observed in the fracture of bulk metallic glasses. We also study the crystallization behavior and the phase and microstructure transformations under isothermal heat treatment of the Hf-based metallic glass.

석영 유리의 파괴 거동에 관한 연구(Ⅱ)

최성대(Seong-Dae Choi),정선환(Seon-Hwan Cheong),권현규(Hyun-Kyu Kwon),정영관(Young-Kwan Jeong),홍영배(Yong-Bae Hong) 한국산업융합학회 2007 한국산업융합학회 논문집 Vol.10 No.4

Glass-to-metal contact should be prevented in the design of any structural glass component. Because glass is extremely brittle and will fracture readily if even a small point load is applied. If the assembly includes a glass component supported by metallic structure, designers should provide a pliable interface of some kind between the two parts. But there happens high demand of glass-to metal contact in semiconductor industries due to adoption of dry cleaning process as one of the good solution to reduce running cost - carry out equipments cleaning with high corrosive and etching gas such as CF4 with keeping process temperature as the same as high service temperature. Therefore the quartz glass have to be received compression by direct contact with metal as the form of weight itself and vacuum pressure and fatigue by vibrations caused by process during the process. In this paper investigation will be carried out on fracture behavior of quartz glass contacted with metal directly under local load and fatigue given by process vibration with apparatus which can give lox\cal load and vibration through PZT ceramics to give guideline to prevent unintended fracture of quartz glass.

Abnormal devitrification behavior and mechanical response of cold-rolled Mg-rich Mg-Cu-Gd metallic glasses

Lee, J.I.,Kim, J.W.,Oh, H.S.,Park, J.S.,Park, E.S. Elsevier 2016 Acta materialia Vol.116 No.-

<P>Abnormal devitrification behavior and mechanical response of Mg75Cu15Gd10 (relatively strong glass former with higher structural stability) and Mg85Cu5Gd10 (relatively fragile glass former with lower structural stability) metallic glasses, fabricated by repeated forced cold rolling, have been investigated. When metallic glasses were cold-rolled up to a thickness reduction ratio of similar to 33%, the heat of relaxation (Delta H-relax.) below T-g of the cold-rolled specimens was reduced, which indicates the formation of local structural ordering via cold rolling due to stress-induced relaxation. The local structural ordering results in abnormal devitrification behavior, such as higher resistance of glass-to-supercooled liquid transition and delayed growth, in the following heat treatment due to increased nuclei density and pinning site. In particular, the fragility index, m, could assist in understanding structural stability and local structural variation by mechanical processing as well as compositional tuning. Indeed, we examine the shear avalanche size to rationalize the variation of the deformation unit size depending on the structural instability before and after cold rolling. The deformation mode in Mg85Cu5Gd10 metallic glass might change from self-organized critical state to chaotic state by cold rolling, which results in unique hardening behavior under the condition for coexisting well distributed local structural ordering and numerous thinner shear deformed areas. These results would give us a guideline for atomic scale structural manipulation of metallic glasses, and help develop novel metallic glass matrix composites with optimal properties through effective mechanical processing as well as heat treatment. (C) 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.</P>

Metallic Glass의 응용기술 동향

박금환 ( Keum Hwan Park ),김영석 ( Young Seok Kim ) 한국공업화학회 2016 공업화학전망 Vol.19 No.4

Metallic glass는 기존의 결정질 금속 소재에 비해 우수한 기계적, 화학적, 자기적 특성들로 인하여 꿈의 신소재로 각광받으며 많은 연구가 이루어져 왔으나 실제 산업계에서 큰 수요증가가 이루어지지 못하였다. 하지만 근래에 들어 Biomedical, 에너지, MEMS (micro-electromechanical system), 및 유연전자 기술 분야 등에서 metallic glass 를 이용하여 우수한 연구 성과들을 발표하면서 실용화에 대한 기대감을 다시금 높이고 있다. 본고에서는 metallic glass의 물성에 대한 간략한 소개와 다양한 분야에서 이루어지고 있는 응용기술을 중심으로 서술하였다.

전기로 분진이 첨가된 유리의 중금속 안정화 특성

은희태,강승구,김유택,이기강,김정환,Eun, Hee-Tai,Kang, Seung-Gu,Kim, Yoo-Taek,Lee, Gi-Kang,Kim, Jung-Hwan 한국세라믹학회 2004 한국세라믹학회지 Vol.41 No.11

전기로 제강분진(EAF dust)이 첨가된 규산염 유리, 붕규산염 유리 그리고 납규산염 유리 내의 중금속 안정화 특성을 독성용출 시험법(TCLP)으로 조사하였다. 또한 XRD와 FT-IR 방법을 통하여 EAF dust 첨가량에 따른 유리의 구조변화가 TCLP 결과에 미치는 영향을 고찰하였다. 모유리에 EAE dust를 30 wt%까지 첨가하여도 규산염 유리, 붕규산염 유리, 납규산염 유리 계열의 시편 모두 결정화가 발생되지 않고 비정질을 나타내었다. TCLP법에 의한 유리시편의 중금속 용출량은 EAF dust의 첨가량과 함께 증가되었다. 중금속 용출이 가장 적은 시편은 규산염 유리 계열이었으며 납규산염 유리 계열의 시편은 붕규산염 유리 계열에 비해 중금속 용출량이 상대적으로 적었다. 단, 납규산염 유리 계열 모유리 조성에 포함되어 있는 납의 영향으로 Pb용출은 납규산염 유리 계열시편에서 가장 많았다. Oxygen/network former ratio 값을 이용하여 같은 계열 시편 간의 화학적 내구성을 비교할 수 있었으나 다른 계열 시편 간에는 적절치 않았다. EAF dust가 첨가되면 규산염 유리 계열의 시편에서는 유리구조 내 Si-O-Si 대칭성이 감소되고 비가교 산소가 증가되어 유리의 구조를 약화시키고 화학적 내구성을 감소시켰다 붕규산염 유리 계열 시편에서 EAF dust가 첨가되면 tetraborate group이 diborate group으로 변화되고 2차원 층상구조인 pyre-와 ortho-borate도 형성되어 결국 구조약화를 가져왔다. 3가지 계열의 유리조성 중에서 EAF dust내의 중금속들을 안정화하는데 가장 적합한 것은 규산염 유리 계열의 시편으로 판단되었다. The stabilizing characteristics of heavy metals in the silicate glass (SD), borosilicate glass (BD), and leadsilicate glass (PD) containing Electric Arc furnace (EAF) dust were studied by the Toxic Characterization Leaching Procedure (TCLP) test. Also, the dependence of the amount of EAF dust upon structural changes of SD, BD, and PD glasses and the TCLP results were investigated by the XRD and FT-IR spectroscopy. In the XRD results, all of SD, BD, and PD specimens containing dust up to 30 wt% were amorphous without crystallizing. In the TCLP test, the concentration of heavy metals leached from the glasses increased with the amount of EAF dust added. The SD specimen series showed the lowest heavy metal leaching and the heavy metal leachate of the PD specimens were lower than those of the BD specimens. But, the Pb leaching from the PD specimens was the highest in the PD glass composition due to the high Pb content. The value of oxygen/network former ratio could be used to compare the chemical durability within the same glass series, but not proper to do between the different glass series. Adding the EAF dust to the SD mother glass, decreased the Si-O-Si symmetry and increased the non-bridging oxygen, which weakened the structure and decreased the chemical durability of glasses. In the BD series glasses, the addition of EAF dust caused the structural changes from tetra-borate group to di-borate group and the formation of the 2-dimensional layer structure of pyre- and ortho- borate, which decreased the chemical durability of glasses. It is concluded that SD series glass among the 3 kinds of glasses is the most effective to stabilize the heavy metals of EAF dust.