Manufacturing and microstructural characterization of sintered nickel wicks for capillary pumps

Abstract

Sintered nickel powder is proposed to be used as porous wicks in heat pipes and capillary pumps. In this work the manufacturing procedure for tubular wicks for capillary pump application is discussed. The porosity, mechanical resistance and roundness of tubular wicks made of carbonila powder, atomized powder and a powder mixture of both are analyzed. A powder mixture was selected as the best raw material. In this case, pore size in the range of 2 to 24 µm and porosity about 50% were measured. First tests carried out in the laboratory, using acetone as the working fluid, show capillary pumping pressures up to 4 kPa and heat fluxes of about 1 W/cm 2 in a two-phase heat transfer loop.

Porous manganese-based magnetocaloric material for magnetic refrigeration at room temperature

“…Following a loose powder sintering technique in an alumina matrix [7], a porous magnetocaloric structure was generated. Synthesized compounds were hand-milled and sieved to obtain MCE particles in the ranges 75-90 mm and 90-125 mm.…”

“…A first attempt to study the fabrication of such porous structures is exploited in this work by using conventional powder metallurgy techniques based on sintering of loose powders. These porous structures are widely characterized by mercury injection poresizer and image analysis techniques [7]. …”

Porous Structures in Heat Pipes

“…Reimbrechta et al used a tap powder sintering technique by using a graphite matrix, to manufacture Ni wicks for capillary pump applications [27]. It shows that the graphite has low interaction with nickel by sintering the nickel powders at common sintering temperatures.…”

Technology of micromatrix posts applied to elimination of initial filling and Newton ring in a microcapillary pumped loop

“…Various experiments using sintered nickel components with fine pore sizes have been performed. 9,10 Small pore sizes have been produced in the manufacturing of wick structures from sintered metal components. 9 Microcapillary pumped loop systems (MCPLs) have recently undergone extensive investigation because of their importance to heat transfer.…”

“…9,10 Small pore sizes have been produced in the manufacturing of wick structures from sintered metal components. 9 Microcapillary pumped loop systems (MCPLs) have recently undergone extensive investigation because of their importance to heat transfer. Many potential configurations and numerous challenges related to transitioning MEMS technologies have been examined to develop a microcooler.…”