Thermal Cycling Behaviour of Dense Monolithic Alumina

Solar Heat for Materials Processing: A Review on Recent Achievements and a Prospect on Future Trends

“…Exposure to the solar radiation can be done almost instantaneously. Some examples of the use of concentrated solar radiation for rapid heating and thermal cycling are available in the literature [60][61][62][63][64].…”

“…The thermal cycling shown in Figure 3, with T max ≈ 1200 • C and T min ≈ 400 • C, was conducted on a group of six circular discs (each of them with 25 mm diameter and 2 mm thickness) made of commercial high-purity dense monolithic Alumina (RAPAL ® 100) [63]. The specimens' layout placed at the focal area of a high-flux solar furnace is depicted in Figure 4 in order to explain the positioning of the discs and the location of the thermocouples that were used to measure the temperature at various locations in the vicinity of the alumina discs.…”

“…During the irradiation, the distribution of temperature was also evaluated using an infra-red camera and its software. Figure 4c depicts an image obtained using an infra-red camera, and it should be remarked that, for achieving a more homogeneous distribution of temperature at the surface of the discs, a device (named "radiation homogenizer") composed of vertical mirrors was placed close to the focal zone [63]. The thermal cycling shown in Figure 3, with Tmax ≈ 1200 °C and Tmin ≈ 400 °C, was conducted on a group of six circular discs (each of them with 25 mm diameter and 2 mm thickness) made of commercial high-purity dense monolithic Alumina (RAPAL ® 100) [63].…”

“…Figure 4c depicts an image obtained using an infra-red camera, and it should be remarked that, for achieving a more homogeneous distribution of temperature at the surface of the discs, a device (named "radiation homogenizer") composed of vertical mirrors was placed close to the focal zone [63]. The thermal cycling shown in Figure 3, with Tmax ≈ 1200 °C and Tmin ≈ 400 °C, was conducted on a group of six circular discs (each of them with 25 mm diameter and 2 mm thickness) made of commercial high-purity dense monolithic Alumina (RAPAL ® 100) [63]. The specimens' layout placed at the focal area of a high-flux solar furnace is depicted in Figure 4 in order to explain the positioning of the discs and the location of the thermocouples that were used to measure the temperature at various locations in the vicinity of the alumina discs.…”

“…During the irradiation, the distribution of temperature was also evaluated using an infra-red camera and its software. Figure 4c depicts an image obtained using an infra-red camera, and it should be remarked that, for achieving a more homogeneous distribution of temperature at the surface of the discs, a device (named "radiation homogenizer") composed of vertical mirrors was placed close to the focal zone [63].…”