재학생의 학교생활 및 개인생활의 문제영역 분석과 상담대책

노무근 三陟大學校 學生生活硏究所 1998 學生生活硏究 Vol.4 No.-

高强度鑄鐵의 製造와 機械的性質에 관한 硏究

盧戊根 三陟大學校 1998 論文集 Vol.31 No.2

It is the purpose of this study to get informations on the mechanical properties of cast iron having different shape of graphite and different additions of Mn and Ni, respectively. Therefore, they were investigated systematically by measuring hardness and tensile strength. The graphite form of cast iron shows spheroidal type, CV type and flake type with increasing holding time after spheroidization treatment. The hardness and tensile strength of cast iron increase with increasing graphite nodularity and amounts of Mn, Ni, contents.

대학홍보전략의 방안에 관한 연구

盧戊根 三陟大學校 2001 論文集 Vol.34 No.2

粒子分散 A1金屬基 複合材料에 關한 硏究

盧戊根 三陟大學校 1997 論文集 Vol.30 No.2

The engulfment of a particle suspended in a melt by a freezing interface requires replacement of two interfaces by a single interface. Since each of these interfaces has a tension associated with it, the process of interface substitution must be energetically feasible for the engulfment of particles to be spontaneous. From a thermodynamic point of view, engulfment is spontaneous when ??, and it is unfavorable when ??. The total free energy change during the process of engulfment is ?? where ?? and ?? are the specific surface energies of the solid-particle and particle-liquid interfaces, respectively. Alternatively, the free energy of adhesion must also be negative for the engulfment to be spontaneous. At slow growth rates and in the absence of external forces, the engulfment or pushing of particles by a freezing interface can be qualitatively predicted on the basis of the above thermodynamic criterion. Particle engulfment and rejection may depend on the fluid mechanics of the solidification process, and on the thermodynamic properties such as interfacial tension, temperature and concentration, and on the thermodynamic properties such as interfacial tension, temperature and concentration, and also on the supersaturation or supercooling of the crystallizing liquid. If the rate of solidification is low and the solid-melt interface is smooth, the thermodynamic effects are to dominate. This study was carried out with the viewpoint of interfacial energy effects on the behavior of Al₂O₃ particles in Al marix.

CV黑鉛鑄鐵의 磨滅特性에 미치는 Mn 및 Ni 微量添加의 影響

盧戊根,申世均,權赫茂 충남대학교 공업교육연구소 1986 論文集 Vol.9 No.1

The Influences of small additions of Mn, Ni and holding time after spheroidization treatment on the wear characteristics of CV graphite cast iron are studied. The main results are summarized as follows. 1) The graphite form of cast iron shows spheroidal type, CV type and flake type with increasing holding time after spheroidization treatment of melt. The graphite form does not change with increasing amounts of Mn and Ni. 2) The hardness and tensile strength of cast iron increase with increasing amounts of Mn and Ni contents. 3) The change in wear mechanism for CV graphite cast iron shows abrasive wear, corrosive wear and adhesive wear with increasing wear speed. 4) Wear resistance of spheroidal graphite cast iron shows the highest value of-all, and CV graphite cast iron shows greater value than flake graphite cast iron. The wear loss of Mn, Ni added CV graphite cast iron decreases with increasing amounts of additives.

Al 複合材料의 固液界面에 미치는 Ti의 影響에 關한 硏究

盧戊根 三陟大學校 産業科學技術硏究所 1999 産業科學技術硏究論文集 Vol.4 No.-

This study was carried out the methods of unidiretional solidification experiments in a countergravitational vertical configuration on premixed Al-Al₂O₃-Ti composites melts under fixed growth conditions of Rate 2.0mm/hr. and gradient of furnace 3.09K/mm. The Ti presence in Al-Al₂O₃composites make Al₂O₃particle engulf readily from liquid composites phase to solid composites phase. This is can be eluidated by increasing of interfaial energy between ceramic Al₂O₃particle and liquid and also can be describe by decreasing of interfacial energy between solid and ceramic particle

주철의 열적 성질에 미치는 흑연형상 및 첨가원소 ( Mn , Ni)의 영향

노무근,권혁무 ( Moo Kun Roh,Hyuk Moo Kwon ) 한국주조공학회 1989 한국주조공학회지 Vol.9 No.1

N/A SGCI(Spheroidal Graphite Cast Iron), CVGCI(CV Graphite Cast Iron) and FGCI(Flake Graphite Cast Iron) having different contents of Mn(0.25%∼0.85%) and Ni(0.3%∼1.2%) were produced, respectively. The thermal expansion and thermal conductivity of the cast iron were investigated in the temperature range of 50℃∼300℃. As the graphite nodularity of the cast iron increases, thermal expansion coefficient increases, thermal conductivity and electrical conductivity to thermal conductivity ratio decrease. The thermal expansion coefficient of the cast iron increases with increasing Mn content and decreases with increasing Ni content. The thermal conductivity of the cast iron decreases with increasing Mn and Ni contents.

주철의 흑연조직 및 기지조직에 관한 연구

盧戊根,金大壽 三陟大學校 1995 論文集 Vol.28 No.1

It is the purpose of this study to get the basic informations on the graphite structure and matrix structure of cast iron having different shape of graphite and different additions of Mn(0.25%∼0.65%) and Ni(0.3%∼1.2%), respectively. The graphite form of cast iron with increasing holding time after spheroidization treatment. The cast iron having 0.85% Mn contents shows the 12% increase of pearlite and 1% decrease of graphite than those of 0.25% Mn contents. The cast iron having 1.2% Ni contents shows the 6% increase of ferrite and 1% increase of graphite than those of Ni not added. Mn distributes mainly at Inter-Cementite and Ni distributes almost uniformly at the ferrite intergranular, ferrite grainbounday, Inter-Cementite and boundary of ferrite and pearlite in the matrix of cast iron having different additions of Mn and Ni.

Aluminium合金熔湯의 冷却速度에 關한 硏究

盧戊根,金大壽 三陟大學校 1994 論文集 Vol.27 No.-

It is the purpose of this study to investigate the relationship between cooling rate of melt, pouring temperature and degree of undercooling by means of casting Al - (5~45%) Cu alloys in the castable mold having the inner diameter of 55mm and in the metallic mold having the inner diameter of 30mm and 40mm, respectively. For investigatig the influences of contents of alloying element on the degree of undercooling the additional amounts of alloying element are varied from the hypoeutectic composition to the hypereutectic composition. The main results obtained are as follows. In the castable mold, the cooling rate of the inner part of the variation of pouring temperature shows the greater value than the center part of the mold by the value of 12℃ /min. In the metallic mold, ø30㎜ mold shows the greater cooling rate than the metallic mold of ø40㎜ by the value of 15℃ /sec, because of having the less amount of volume and surface area of the melt. The cooling rate of the melt cast in metallic mold having the same composition and volume shows 45 times larger cooling rate than the castable mold and cooling rate decreases as the pouring temperature increases irrespective of mold materials. The equilibrium solidification and 19℃ in Al-Cu alloy shows the less value of 16℃ in the center part of the mold and 19℃ in the outside part of the mold in this experimental casting. The degree of undercooling increases as the cooling rate of melt and alloying element increases.

Wear mechanism에 미치는 Graphite형상의 영향에 관한 연구

盧戊根,金大壽 三陟大學校 1996 論文集 Vol.29 No.2

It is the purpose of this study to find the basic informations on the wear mechanism and wear characteristics of cast iron having different additions of Manganese and Nickel. The graphite form of cast iron shows spheroidal type, CV type and flake type with increasing holding time after spheroidization treatment. The hardness and tensile strength of cast iron increase with increasing graphite nodularity and amounts of Mn, Ni contents respectively. The change in wear mechanism with increasing abrasion speed for cast iron shows abrasive wear, oxidative wear and adhesive wear. Wear resistance of spheroidal geaphite cast iron shows the highest value of all, and CV graphite cast iron shows greater value than flake graphite cast iron. The wear loss of Mn, Ni added iron decreases with increasing amounts of additions.