• Journal of the Korean institute of surface engineering
• /
• v.43 no.3
• /
• pp.127-131
• /
• 2010

Adhesion of DLC film is very significant property that exhibits wear resistance, chemical inertness and high hardness when being deposited to metal substrate. This study was considered that change adhesion of DLC film produced by Plasma Enhanced Chemical Vapor Deposition can be presented through inserting interlayer (Cr, Si-C:H). The thickness of interlayer was result of changing adhesion and residual stress. It was showed that the maximum 12 N of adhesion is on DLC film of Cr interlayer, and that a tendency is to be increased residual stress depend on the thickness. DLC film of Si-C:H interlayer represented 16 N of adhesion at $1{\mu}m$, whereas adhesion is decreased when the thickness is increased. For the interlayer at multi-layer, it was the best that adhesion of Cr/Si-C:H/DLC film was 33 N. Si-C:H interlayer at DLC film controled adhesion of the whole film. It was relaxed the internal stress of DLC film produced by inserting Cr, Si-C:H interlayer.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.8 no.4
• /
• pp.821-825
• /
• 2004

The a-Si：H TFTs decreasing parasitic capacitance of source-drain is fabricated on glass. The structure of a-Si：H TFTs is inverted staggered. The gate electrode is formed by patterning with length of 8 ${\mu}m∼16 ${\mu}m. and width of 80∼200 ${\mu}m after depositing with gate electrode (Cr) 1500 under coming 7059 glass substrate. We have fabricated a-SiN：H, conductor, etch-stopper and photoresistor on gate electrode in sequence, respectively. The thickness of these thin films is formed with a-SiN：H (2000 ), a-Si：H(2000 ) and n+a-Si：H (500). We have deposited n+a-Si：H ,NPR(Negative Photo Resister) layer after forming pattern of Cr gate electrode by etch-stopper pattern. The NPR layer by inverting pattern of upper gate electrode is patterned and the n+a-Si：H layer is etched by the NPR pattern. The NPR layer is removed. After Cr layer is deposited and patterned, the source-drain electrode is formed. The a-Si：H TFTs decreasing parasitic capacitance of source-drain has channel length of 8 ~20 ${\mu}m and channel width of 80∼200 ${\mu}m. And it shows drain current of 8 ${\mu}A at 20 gate voltages, Ion/Ioff ratio of 108 and Vth of 4 volts.

• Korean Journal of Materials Research
• /
• v.4 no.6
• /
• pp.669-680
• /
• 1994

Oxidation behaviour of TiAl intermetallic compounds with the addition of Cr, V, Si, Mo, or Nb was investigated at 900~$1100^{\circ}C$ under the atmospheric environment. The reaction products were examined by XRD, SEM equipped with WDX. The weight gain by continuous oxidation increased with the addition of Cr or V, but there was less weight gain when Mo, Si or Nb was added individually. he oxidation rate of Cr- or V-added TiAl was always larger than that of TiAI. However, oxidation rate of Si-, Mo- or Nb-added TiAl was almost same or smaller than that of TiAI. Thus, it is concluded that the addition of Cr or V did not improve the oxidation resistance, whereas the addition of Si, Mo or Nb improved the oxidation resistance. Oxides formed on TiAl with Mo, Si, and Nb were found to be more protective, resulting from the decrease in diffusion rate of the alloying elements and oxygen. Nb strengthened the tendency to form $AI_{2}O_{3}$ in the early stage of oxidation, due to the continuous $AI_{2}O_{3}$ layer formation and dense $Tio_{2}+AI_{2}O_{3}$ layer. According to the Pt-marker test of TiAI- 5wt%Nb, oxygen diffused mainly inward while oxides were formed on the substrate surface. Upon thermal cyclic oxidation at $900^{\circ}C$, it is shown that the addition of Cr or Nb improved the adherence of oxide scale to the substrate.

• Proceedings of the Korean Magnestics Society Conference
• /
• 2001.10a
• /
• pp.106-107
• /
• 2001

• Transactions of Materials Processing
• /
• v.8 no.3
• /
• pp.327-327
• /
• 1999

The oxidation behavior of 60%Cu-40%Zn brass haying small amounts of Zr, Cr, Mg, Al, and Si was studied between 873 and 1043 K in air. The alloying element of Mg was harmful, while other alloying elements were beneficial to oxidation resistance. Particularly, the simultaneous addition of Al and Si decreased the oxidation rate drastically. During oxidation, Zr formed ZrO₂, Cr formed CuCr₂O₄, Mg formed MgO, Al formed A1₂CuO₄, and Si formed amorphous SiO₂. These oxides were incorporated in the oxide scale composed predominantly of ZnO. The oxide scales formed on all the tested alloyswere prone to cracking, wrinkling, and spallation.

• Proceedings of the Korean Magnestics Society Conference
• /
• 2004.12a
• /
• pp.91-92
• /
• 2004

• Journal of the Korean Ceramic Society
• /
• v.46 no.4
• /
• pp.405-412
• /
• 2009

In high temperature ceramic glazes, a stable range of pink-red colors that produced $Cr_2O_3-SnO_2-CaO-SiO_2$ pigments were factored by Cassiterite($SnO_2$) and Malayaite($CaSnSiO_5$) by $Cr_2O_3$. The experiment examined the influence of $CrCl_3$, a Sn-Cr substitution added with a mineralizer ($H_3BO_3$), as a chromophore in pigments. The experiment also studied the effect of $H_3BO_3$ (2 wt%) when added to malayaite($CaSnSiO_5$) to see if the crystalline reaction will increase. $Cr_2O_3$ was also substituted with $CrCl_3$ in order to prove how much influence $CrCl_3$ had on the $H_3BO_3$. Malayaite and cassiterite were the basic compound materials and the experiment was conducted both with and without mineralizers (2 wt% of $H_3BO_3$). Each compound was synthesized at 800, 1000, 1200, 1300, 1400, $1500^{\circ}C$ for 2 h. Synthesized pigments were analyzed by XRD, FT-IR and UV-Vis. The temperature variation produced two crystal phases that showed the different engaging effects of Cr oxidation. $CrCl_3$ produced a better effect on the malayaite crystal phase, resulting in a more defined pigmentation of the pink-red coloration compared to $Cr_2O_3$.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.25 no.11
• /
• pp.1294-1303
• /
• 1988

Electron and hole traps in semi-insulating GaAs with activation energies ({\Delta}E_r) ranging from 0.16 $\pm$ 0.01 to 0.98 $\pm$ 0.01 eV, have been detected and characterized by photo-induced current transient measurements. SI undoped GaAs has fewer deep levels than SI GaAs: Cr. The thermal capture cross section and density of the traps have been estimated and some of the centers have been related to native defects. In particular, the activation energy of the compensating Cr, and "0" levels in semi-insulating GaAs were accurately measured. The transient measurements were complemented by Hall measurements at T > 300K and photocurrent spectra measurements. The transition energies for the deep compensating levels obtained by the analyses of data from these measurements, when compared with those from the transient measurements, indicate negligible lattice-coupling of these centers. Analysis of the transport data also indicates that neutral impurity scattering plays a significant role in semi-insulating materials at high temperatures.

• Journal of Korea Foundry Society
• /
• v.5 no.4
• /
• pp.271-282
• /
• 1985

In order to investigate the mold reaction characteristics of Mn steel and Cr steel castings individually, the mold reaction products were examined by scanning electron microscopy, electron prove microanalyzer and X-ray diffractometer. From this experiment, the results were summarized as follows: 1) The mold reaction depth increased with increase of Mn content, while it decreased with increase of Cr content. 2) Mold reaction depth decreased with Mn content at $1200^{\circ}C$. 3) Mn, among the reaction products, forms a low fusion silicate, Mn $O.SiO_2$ while Cr forms a stable oxide, $CrO_3$ which hindering the reaction between FeO and $SiO_2$ thus the formation of $FeO.SiO_2$ was depressed.

• Journal of Technologic Dentistry
• /
• v.14 no.1
• /
• pp.119-132
• /
• 1992

This paper aims to investigate the effect of B and Si upon the mechanical properties, microstructure and corrosion resistance of Co-Cr base alloy. Ten groups of alloy ingot ingot with various contents of B and Si were remelted by high frequency electrical induction furnace and cast into tensile specimen of ADA Specification No. 14 Tensile and hardness test were carried out by Amsler and Rockwell hardness tester(R-30N), respectively. The microstructures of specimen were observed by SEM. The results obtained are summarized as follows : 1. As B content is increased, tensile strength, yield strength and Rockwell hardness number(R-30N) are also increased significantly, while the elongation is decreased significantly. 2. As Si contect os increased, no significant chang in tensile strength is noticed, yield strength is slightly decreased, but Rockwell hardness number(R-30N) is moderately in creased, Elongation marks maxium value with 1% Si content while with more than 1% Si it is decreased. 3. As B content is increased corrosion resistance is decreased and is at best with 1.5% B content. Corrosion resistance is increased with the increase of Si content and the alloys with Si over 3.0% showed corrosion resistance. 4. As B content increased, precipitates are increased in number at grain boundaries. The grain size tends to become coarse with the increase of Si content. 5. Co rich-Cr alloy is present through matrix whereas at the grain boundaries Cr base precipitates are primarily formed.