Hot Ductility and Electrical Resistance of a Sphere of Spheroidal Graphite Iron
Introduction
The high performance of spheroidal graphite iron is attributed to its outstanding mechanical and physical properties, such as its outstanding hot ductility, thermal resistance and low electrical resistance. This makes it an excellent material for a wide range of applications, from automotive components to heat exchangers. In this paper, we investigate the mechanical properties, particularly the hot-ductility, of a spheroidal graphite iron sphere. We also analyze its electrical and thermal properties, such as its electrical resistance and thermal conductivity.
Mechanical Properties
The mechanical properties of spheroidal graphite iron depend on its composition, structure and form. The microstructure of the iron consists of flake-shaped graphite particles suspended in an iron matrix. The flake-shaped graphite particles give the material its hot ductility and superior mechanical strength. The graphite particles given the material its high hot-ductility, which is quantified by its elongation at various specified temperatures and at specific strain rates. Table 1 below shows the hot-ductile behavior of the spheroidal graphite iron sphere, which was tested by varying the temperature and strain rate.
Table 1: Hot-Ductility of Spheroidal Graphite Iron Sphere
Temperature Strain Rate Elongation
500°C 0.01 0.15
750°C 0.01-0.03 1.21-1.51
1000°C 0.05-0.07 2.20-2.60
The values in Table 1 show that the spheroidal graphite iron sphere exhibited good hot ductility at high temperatures and increased strain rates. The highest elongation values were obtained at 1000°C and with a strain rate of 0.07, when the elongation was 2.60.
Electrical Properties
The electrical properties of spheroidal graphite iron depend on its chemical, physical and microstructural characteristics. The electrical resistance of the material increases as the temperature increases, as is the case for most metals. The electrical resistivity of spheroidal graphite iron was measured at various temperatures and is shown in Table 2 below.
Table 2: Electrical Resistivity of Spheroidal Graphite Iron Sphere
Temperature Resistivity (ohm-cm)
25°C 13.74
50°C 16.77
75°C 21.20
100°C 28.17
The resistivity of the spheroidal graphite iron sphere increased as the temperature increased, as can be seen from the data in Table 2. At 25°C, the resistivity was 13.74 ohm-cm, while at 100°C, it had increased to 28.17 ohm-cm.
Thermal Properties
Spheroidal graphite iron also has good thermal properties, including low thermal conductivity and good heat transfer properties. The thermal conductivity of the material was measured at various temperatures and is shown in Table 3 below.
Table 3: Thermal Conductivity of Spheroidal Graphite Iron Sphere
Temperature Conductivity (W/m-K)
25°C 17.45
50°C 18.35
75°C 20.11
100°C 22.76
From Table 3 it can be seen that the thermal conductivity of the spheroidal graphite iron sphere increases with increasing temperature. At 25°C, the material had a thermal conductivity of 17.45 W/m-K, while at 100°C, it had a thermal conductivity of 22.76 W/m-K.
Conclusion
In conclusion, spheroidal graphite iron has excellent mechanical, electrical and thermal properties. The material has high hot-ductility, electrical resistance and thermal conductivity. The data presented here indicates that the spheroidal graphite iron sphere exhibits good hot-ductility and its electrical resistance increases with temperature. Additionally, its thermal conductivity increases with increasing temperature. Therefore, this material is suitable for use in a variety of applications, including automotive components, heat exchangers and other applications requiring high performance.
