“…The small pores transferred the heat conveniently as compared to large pores. 34 First, the thermal conductivity remains constant and further decreased with respect to increase in heating rate.…”
Section: Resultsmentioning
confidence: 98%
“…The cylindrical samples (10 mm ∅ and 30 mm length) were fabricated to measure the thermal conductivity by hot-plate method based on Fourier law of heat transfer. 33–35 The schematic diagram of the setup to measure thermal conductivity is described in Figure 4. Figure 4.Thermal conductivity measurement setup schematic diagram.…”
Section: Experimental Methodsologymentioning
confidence: 99%
“…35 The air acts as gas in pores for the gaseous conduction with thermal conductivity of 0.025 W/mK low as compared to solid copper at atmospheric pressure. 34 Also, the heat transfer within samples having relative density more than 0.2 has insignificant effect of gaseous conduction. 35 The micron size particles were used for the sintering purpose and resulted in micron size pores.…”
In the present paper, mechanical and thermal properties of rapidly manufactured copper parts were studied. The combination of three-dimensional printing and ultrasonic assisted pressureless sintering was used to fabricate copper parts. First, the ultimate tensile strength and thermal conductivity were compared between ultrasonic assisted and conventional pressureless sintered samples. The homogenously mixing of particles and local heat generation by ultrasonic vibrations promoted the sintering driving process and resulted in better mechanical and thermal properties. Furthermore, response surface methodology was adopted for the comprehensive study of the ultrasonic sintering parameters (sintering temperature, heating rate, and soaking time with ultrasonic vibrations) on ultimate tensile strength and thermal conductivity of the fabricated sample. Analysis of variance was performed to identify the significant factors and interactions. The image processing method was used to identify the surface porosity at different parameter levels to analyse the experimental results. High ultimate tensile strength was obtained at high sintering temperature, long soaking time, and slow heating rate with low surface porosity. After 60 min of soaking time, no significant effect was observed on the thermal conductivity of the fabricated sample. The significant interactions revealed less effect of soaking time at low sintering temperatures for ultimate tensile strength and less effect of heating rate at low sintering temperatures for thermal conductivity. Multi-objective optimization was carried out to identify parameters for maximum ultimate tensile strength and maximum thermal conductivity.
“…The small pores transferred the heat conveniently as compared to large pores. 34 First, the thermal conductivity remains constant and further decreased with respect to increase in heating rate.…”
Section: Resultsmentioning
confidence: 98%
“…The cylindrical samples (10 mm ∅ and 30 mm length) were fabricated to measure the thermal conductivity by hot-plate method based on Fourier law of heat transfer. 33–35 The schematic diagram of the setup to measure thermal conductivity is described in Figure 4. Figure 4.Thermal conductivity measurement setup schematic diagram.…”
Section: Experimental Methodsologymentioning
confidence: 99%
“…35 The air acts as gas in pores for the gaseous conduction with thermal conductivity of 0.025 W/mK low as compared to solid copper at atmospheric pressure. 34 Also, the heat transfer within samples having relative density more than 0.2 has insignificant effect of gaseous conduction. 35 The micron size particles were used for the sintering purpose and resulted in micron size pores.…”
In the present paper, mechanical and thermal properties of rapidly manufactured copper parts were studied. The combination of three-dimensional printing and ultrasonic assisted pressureless sintering was used to fabricate copper parts. First, the ultimate tensile strength and thermal conductivity were compared between ultrasonic assisted and conventional pressureless sintered samples. The homogenously mixing of particles and local heat generation by ultrasonic vibrations promoted the sintering driving process and resulted in better mechanical and thermal properties. Furthermore, response surface methodology was adopted for the comprehensive study of the ultrasonic sintering parameters (sintering temperature, heating rate, and soaking time with ultrasonic vibrations) on ultimate tensile strength and thermal conductivity of the fabricated sample. Analysis of variance was performed to identify the significant factors and interactions. The image processing method was used to identify the surface porosity at different parameter levels to analyse the experimental results. High ultimate tensile strength was obtained at high sintering temperature, long soaking time, and slow heating rate with low surface porosity. After 60 min of soaking time, no significant effect was observed on the thermal conductivity of the fabricated sample. The significant interactions revealed less effect of soaking time at low sintering temperatures for ultimate tensile strength and less effect of heating rate at low sintering temperatures for thermal conductivity. Multi-objective optimization was carried out to identify parameters for maximum ultimate tensile strength and maximum thermal conductivity.
“…However, replication methods provide a high repeatability of the produced structure jointly with the ability to control the porosity of the product. For example, Abuserwal et al reported that effective thermal conductivity decreases with the increase in porosity [ 8 ]. Goodall et al revealed the plasticity size effect.…”
Porous materials are widely employed in a wide variety of industrial applications due to their advanced functional performance. Porous aluminum is among the most attractive metallic materials. It can be produced using repeatable methods involving a replicated Al foam that also provides porosity control. In this work, a highly porous replicated Al foam was fabricated. First, the model of multifunctional packing density was used and corrected to select the appropriate space holders. Then, Al foam was produced using a double-granular sodium chloride space holder. The obtained results showed a maximum porosity of 65% that was achieved using a mix of coarse, irregular granules with spherical granules of intermediate size.
“…Research into new materials for active thermal management has focused mainly on metal and carbon/graphite foams as they show interesting physical properties, such as low density and high specific area per unit volume, plus decent thermal conductivity [3][4][5][6][7][8]. Several foam manufacturing techniques have been developed in the last years [9,10].…”
The recent progress made in active thermal management for electronics demands the development of new open-pore foam materials with excellent thermal performance that result from the combination of high thermal conductivity (≥70 W/mK) and the lowest possible fluid pressure drop. The foams considered to date in the literature do not meet these conditions. In this work, a new class of two-phase composite foam materials, which contain graphite flakes and aluminium, were fabricated by the gas pressure liquid metal infiltration method. These materials were fabricated in two main microstructures: i) aluminium foam with oriented graphite flakes in struts; ii) alternating layers of oriented graphite flakes and aluminium foam.The resulting materials exhibited thermal conductivities within the 60-290 W/mK range, and power dissipation capacities up to 325% higher than those for conventional aluminium foams, with pressure drops kept at convenient values for the most demanding active thermal management applications.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
