Experimental investigation on flow boiling performance of porous heat sinks produced by powder metallurgy

Porous copper plates were made for microchannel heat sinks in this thesis study. In the production process, copper powders of various sizes were used, and powder metallurgy steps were followed. Sintering temperature, time, pressure, and powder size were the factors influencing porosity level and volume, which were determined by using the Taguchi experimental design method. The experiments used copper powders of 5 μm and 50 μm sizes. The powders were compressed in the mold at 50 and 60 bars respectively, and they were sintered for 30 and 60 minutes at 700 °C and 900 °C. Utilizing the Taguchi method, the L8 orthogonal array was selected to target the surface with the highest porosity. Analysis of variance was used to calculate the effect ratios of each design element on porosity (ANOVA). The thermal, mechanical, and microstructure characteristics of the generated samples were examined and compared. This paper reports on a new experimental investigation on flow boiling in coolers with parallel microchannels and a rectangular cross-section created using a traditional powder metallurgy process. Microchannel coolers have 20 mm by 20 mm dimensions. Every cooler utilized in the testing has the same number and dimensions for the channels. Deionized water was used for the boiling flow tests, with mass flux of 238.2 and 430.32 kg/m 2 s. At 80°C, the liquid totally evaporates and enters the heat sink. The heat fluxes used in the tests were 46.5 and 61.5 W/cm 2 , and they were conducted under constant heat flux conditions. According to experimental research, the heat transfer coefficients in the heatsink with the largest porosity are 28–33.3 percent greater than those in the heatsink made entirely of copper. The experimental heat transfer coefficients show that they go down with increasing heat flux and steam quality and up with flow rate. Conversely, the coolant sample exhibiting the largest porosity showed 1.5 times higher pressure drop values than the pure copper cooler. In this study, an experimental investigation was conducted on the effect of solid surface thermophysical properties on heat transfer properties in flow boiling in microchannels. Within the scope of the study, heat and flow experiments were carried out on eight microchannel heat sinks with different porosity that we produced with the principle of powder metallurgy.