• Korean Journal of Materials Research
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• v.17 no.9
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• pp.484-488
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• 2007

Mo(Ti) alloy and pure Cu thin films were subsequently deposited on $SiO_2-coated$ Si wafers, resulting in $Cu/Mo(Ti)/SiO_2$ structures. The multi-structures have been annealed in vacuum at $100-600^{\circ}C$ for 30 min to investigate the outdiffusion of Ti to Cu surface. Annealing at high temperature allowed the outdiffusion of Ti from the Mo(Ti) alloy underlayer to the Cu surface and then forming $TiO_2$ on the surface, which protected the Cu surface against $SiH_4＋NH_3$ plasma during the deposition of $Si_3N_4$ on Cu. The formation of $TiO_2$ layer on the Cu surface was a strong function of annealing temperature and Ti concentration in Mo(Ti) underlayer. Significant outdiffusion of Ti started to occur at $400^{\circ}C$ when the Ti concentration in Mo(Ti) alloy was higher than 60 at.%. This resulted in the formation of $TiO_2/Cu/Mo(Ti)\;alloy/SiO_2$ structures. We have employed the as-deposited Cu/Mo(Ti) alloy and the $500^{\circ}C-annealed$ Cu/Mo(Ti) alloy as gate electrodes to fabricate TFT devices, and then measured the electrical characteristics. The $500^{\circ}C$ annealed Cu/Mo($Ti{\geq}60at.%$) gate electrode TFT showed the excellent electrical characteristics ($mobility\;=\;0.488\;-\;0.505\;cm^2/Vs$, on/off $ratio\;=\;2{\times}10^5-1.85{\times}10^6$, subthreshold = 0.733.1.13 V/decade), indicating that the use of Ti-rich($Ti{\geq}60at.%$) alloy underlayer effectively passivated the Cu surface as a result of the formation of $TiO_2$ on the Cu grain boundaries.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.11
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• pp.1600-1604
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• 2017

Mo-Cu alloys have been widely used for heat sink materials, vacuum technology, automobile and many other applications due to their excellent physical and electronic properties. Especially, Mo-Cu composites with 5~20 wt% copper are widely used for the heavy duty service contacts due to their excellent properties like low coefficient of thermal expansion, wear resistance, high temperature strength and prominent electrical and thermal conductivity. In most of the applications, high dense Mo-Cu materials with homogeneous microstructure are required for high performance, which has led in turn to attempts to prepare ultra-fine and well-dispersed Mo-Cu powders in different ways, such as spray drying and reduction process, electroless plating technique, mechanical alloying process and gelatification-reduction process. However, most of these methods were accomplished at high temperature (typically degree), resulting in undesirable growth of large Cu phases; furthermore, these methods usually require complicated experimental facilities and procedure. In this study, Mo-Cu alloying were prepared by planetary ball milling (PBM) and spark plasma sintering (SPS) and the effect of Cu with contents of 5~20 wt% on the microstructure and properties of Mo-Cu alloy has been investigated.

• Journal of Surface Science and Engineering
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• v.53 no.6
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• pp.343-350
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• 2020

The degradation of mechanical properties of nitride coatings to steel substrates is one of the main challenges for industrial applications. In this study, plasma nitriding treatment was used in order to increase the mechanical properties of Mo-Cu-N coating to the H13 tool steel. The nanostructured Mo-Cu-N coating was deposited using pulsed DC magnetron sputtering method with a single alloy Mo-Cu target. Mechanical properties of MoN-Cu coated samples after nitriding were found to be relatively better than non-nitrided MoN-Cu coating.

• Archives of Metallurgy and Materials
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• v.64 no.2
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• pp.539-542
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• 2019

Pre-alloyed Astaloy CrL^TM (Fe-1.5 wt% Cr-0.2 wt% Mo), a commercial Fe-based alloy powder for high strength powder metallurgy products, was sintered and hot forged with additions of 0.5 wt% C and 0~2 wt% Cu. To investigate the influence of various Cu contents, the microstructural evolution was characterized using density measurements, scanning electron microscope (SEM) and electron backscatter diffraction (EBSD). Transverse rupture strength (TRS) was measured for each composition and processing stage. The correlation between Cu additions and properties of sinter-forged Fe-Cr-Mo-C alloy was discussed in detail.

• Journal of the Korean Magnetics Society
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• v.12 no.1
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• pp.30-33
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• 2002

The Effects of Co-substitution in the nanocrystalline Nd-Fe-B-Mo-Cu alloys were investigated. $\alpha$-Fe based nanocrystalline Nd-Fe-B-Mo-Cu alloys were prepared by crystallization process of amorphous Nd-Fe-B-Mo-Cu alloy produced by rapid solidification process. The substitution of Co resulted in the decrease of grain size and improves the hard magnetic properties. The remanence, coercivity, and Curie temperature of nanocrystalline N $d_4$(F $e_{0.85}$ $Co_{0.15}$)$_{82}$ $B_{10}$M $o_3$Cu alloy showed more improved magnetic properties than those of Co-free alloy. The grain size was measured to be about 15 nm. The coercivity, remanence and maximum energy product were 239 kA/m, 1.41, and 103.5 kJ/ $m^3$, respectively, for the nanocrystalline N $d_4$(F $e_{0.85}$ $Co_{0.15}$)$_{82}$ $B_{10}$M $o_3$Cu alloy annealed for 0.6 ks at 640 $^{\circ}C$.

• Journal of Powder Materials
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• v.10 no.3
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• pp.164-167
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• 2003

The mechanical alloying effect has been studied on the three Cu-based alloy systems with a positive heat of mixing. The extended bcc solid solution has been formed in the Cu-V system and an amorphous phase in the Cu-Ta system. However, it is round that a mixture of nanocrystalline Cu and Mo Is formed in the Cu-Mo system. The neutron diffraction has been employed at a main tool to characterize the detailed amorphization process. The formation of an amorphous phase in Cu-Ta system can be understood by assuming that the smaller Cu atoms preferentially enter into the bcc Ta lattice during ball milling.

• Journal of Technologic Dentistry
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• v.36 no.3
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• pp.141-147
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• 2014

Purpose: Dental casting #Gr I (Co-25Cr-5Mo-3Sn-1Mn-1Si), #Gr II (Co-25Cr-5Mo-5Cu-1Mn -1Si) and #Gr III (Co-25Cr-5Mo-3Sn-5Cu-1Mn-1Si) master alloys of granule type were manufactured the same as manufacturing processes for dental casting Ni-Cr and Co-Cr-Mo based alloys of ingot type. These alloys were analyzed melting processes with heating time of high frequency induction centrifugal casting machine using infrared thermal image analyzer. Methods: These alloys were manufactured such as; alloy design, the first master alloy manufatured using vacuum arc casting machine, melting metal setting in crucible, melting in VIM, pouring in the mold of bar type, cutting the gate and runner bar and polishing. These alloys were put about 30g/charge in the ceramic crucible of high frequency induction centrifugal casting machine and heat, Infrared thermal image analyzer indicated alloys in the crucible were set and operated. Results: The melting temperatures of these alloys measuring infrared thermal image analyzer were decreased in comparison with remanium$^{(R)}$ GM 800+, vera PDI$^{TM}$, Biosil$^{(R)}$ f, WISIL$^{(R)}$ M type V, Ticonium 2000 alloys of ingot type and vera PDS$^{TM}$(Aabadent, USA), Regalloy alloys of shot type. Conclusion: Co-Cr-Mo based alloy in addition to Sn(#Gr I alloy) were decreased the melting temperature with heating time of high frequency induction centrifugal casting machine using infrared thermal image analyzer.

• Journal of the Korean Magnetics Society
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• v.7 no.1
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• pp.44-48
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• 1997

The nanocrystalline Nd-Fe-B alloys with low Nd content were prepared by rapid solidification technique. The alloys consist of both$\alpha$-Fe as the main phase and $Nd_2Fe_{14}B_1$ as a secondary phase and have an ultrafine grain structure of about 30 nm. The addition of Ga in $Nd_4Fe_{82}B_{10}Mo_3Cu_1$ alloy increases remanence up to 1.29 T and improves squareness. The nanocrystalline $Nd_5Fe_{81}B_9Mo_3Cu_1Ga_1$ alloy has a volume fraction of $Nd_2Fe_{14}B_1$ phase of around 35% due to the increase of Nd content and shows an improved coercivity. The remanence, coercivity and energy product of optimally annealed nanocrystalline $Nd_5Fe_{81}B_9Mo_3Cu_1Ga_1$ alloy are 1.24 T, 257.4 kA/m (3.23 kOe), and 100.3 kJ/ ㎥ (12.6 MGOe), respectively.

• Journal of Powder Materials
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• v.26 no.2
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• pp.112-118
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• 2019

Infiltration is a popular technique used to produce valve seat rings and guides to create dense parts. In order to develop valve seat material with a good thermal conductivity and thermal expansion coefficient, Cu-infiltrated properties of sintered Fe-Co-M(M=Mo,Cr) alloy systems are studied. It is shown that the copper network that forms inside the steel alloy skeleton during infiltration enhances the thermal conductivity and thermal expansion coefficient of the steel alloy composite. The hard phase of the CoMoCr and the network precipitated FeCrC phase are distributed homogeneously as the infiltrated Cu phase increases. The increase in hardness of the alloy composite due to the increase of the Co, Ni, Cr, and Cu contents in Fe matrix by the infiltrated Cu amount increases. Using infiltration, the thermal conductivity and thermal expansion coefficient were increased to 29.5 W/mK and $15.9um/m^{\circ}C$, respectively, for tempered alloy composite.

• Proceedings of the Korean Magnestics Society Conference
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• 1991.05a
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• pp.53-54
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• 1991