Энергоёмкость механического диспергирования

Abstract

Измерено повышение температуры медного образца при трении с малой скоростью по абразиву. Установлено наступление теплового равновесия. Найдены: работа, совершенная против сил трения, и полученная образцом за то же самое время теплота. Обе величины имеют один порядок. Удельные их значения близки к энергии сублимации. Они сопоставлены с последней для шестнадцати исследованных металлов. Приведен возможный механизм, оправдывающий высокие энергетические затраты при диспергировании. The article presents the results of experiments made to determine the work spent on the conversion of a substance mass unit into powder in abrasive friction – dispersion specific energy of the agent. It is great and has the order of the sublimation energy for all investigated metals, that is, it is sufficient to convert the resulting powder into vapour. The account of the deformed layer mass beneath the friction surface reduces the specific job without changing its order. During friction not only the test body, but also the abrasive is destroyed and it continuously carries away the heat produced during friction from the friction zone. Therefore, the share of energy costs in the formation of the metal powder can be substantially less than the work of friction which is used to calculate the dispersion specific energy. The article describes experiments which enabled to evaluate the heat produced by the sample. It turns out to be about half the work of friction, and its specific value has, therefore, the order of the sublimation energy. The table is shown in which specific energy values found for sixteen pure metals are compared to the energy of their sublimation. In transition from metal to metal both values change still remaining close to each other. The paper presents a possible mechanism of the process which enables metal to transform heat into energy comparable to the energy of its sublimation.