Capillary structures mechanical properties in respect to functioning conditions in heat pipes

Mechanical properties of capillary structures and their reliable attachment to the inner surface of heat pipes play an important role in a wide temperature range. Reliability of operation of heat pipes depends on the strength of the capillary structure. The article presents the results of an experimental study of the effect of various parameters on the mechanical properties of metal-fiber capillary structure made of stainless steel. The studies of the break of capillary structure were carried out on a special test bench that helped to determine with high accuracy the elongation of the samples under mechanical loads. We have studied two types of capillary structures with diameters of fibers 8 and 30mkm and porosity in the range of 88% to 98%. The results showed that the strength of the structure depends heavily on the fiber diameter, porosity and temperature. The decrease of the fibers diameters, increase of porosity and temperature aggravated the mechanical properties of capillary structures. These results can be used by designers of heat pipes, who operate in a wide temperature range.