V.V. Prasitskiy – Dr. Sc. (Eng.), Director of «Ecolyum-Voshod» (Kaluga). E-mail: email@example.com
Analysis of technologies for producing psevdoalloys molybdenum-copper and tungsten-copper shows that the best results are obtained by using the method of infiltration: infiltration of molten copper porous structure of the refractory phase.
In domestic practice, the mass production of psevdoalloys materials used combined method comprising mixing the starting components (copper powder and refractory phase) forming a powder mixture in the form of tape on the powder mills, sintering powders to obtain porous preform and subsequently compressing the sintered preform to obtain a satisfactory level of residual porosity of the final material.
Since, in this process practically can not perform a number of requirements, such as to ensure conditions of wetting, the starting powder mixture introduced into a variety of additives. In the first place greatly reduced level of one of the main parameters of the material – the thermal conductivity. Furthermore, due to the impact of the rolling mill rolls, a specific structure of the material is created leading to substantial anisotropy of its properties.
For example, the results of changes in the thermal conductivity of molybdenum-copper psevdoalloys manufactured without the use of nickel and its use, are very different, ie increasing the number of non-core natural materials reduces the thermal conductivity.
The analysis shows that, despite the long history of existence, produced domestic materials used in the manufacture of electronic components have parameters significantly lagging behind the potentially possible.
Reason for the lag is due to insufficient study of the properties of the materials used, as well as a set of interrelated physical processes in the manufacture of heat transfer compositions.
This article describes the results of studies that allow technologically obtain composite materials based on molybdenum, tungsten and copper with parameters close to the theoretically possible. Also found patterns that express the relationship of the basic physical parameters of the manufacturing process with the characteristics of these materials.
Particular attention is drawn to the resource and environmental safety of the proposed processes.