Vol. 7 No. 1 (2024)

Open Access

Review

Article ID: 591

Impulse as a true measure of inertia

by Valeriy Abramovich Etkin

Insight - Mechanics, Vol.7, No.1, 2024; 125 Views, 46 PDF Downloads

Based on the system-energodynamic method of analyzing natural and technological processes, the necessity of abandoning the paradigm of homogeneity and isotropy of space filled with matter is substantiated, and a retrospective analysis of the state of mechanics is given. The principles of the determinism of the state and the opposite direction of processes in inhomogeneous (internally non-equilibrium) systems are formulated and proved. The inevitability of the emergence of an oscillatory form of energy in them and the need to consider the latter in the law of its conservation are revealed. In this way, the necessity and possibility of generalizing all three “beginnings” of Newton’s mechanics and considering irreversibility in its equations with the introduction of the “force” efficiency of mechanical processes are shown. The non-equivalence of the momentum to Descartes’ momentum is revealed, and the invariance of the mass in acceleration is proved. It is shown that the true measure of the inertial properties of a substance is the impulse, not the mass, and a generalization of the concept of inertia to non-mechanical forms of motion is proposed. The principle of interconvertibility of the oscillatory, translational, and rotational components of the impulse of internal motion in isolated systems is proved, and thus the possibility of creating a new class of propellers in outer space on this basis is substantiated.

Open Access

Review

Article ID: 584

Development of pressure infiltration preparation of metal matrix composites

by Haofeng Zhao, Lingfeng Zhang, Yiheng He, Zhiguo Ma

Insight - Mechanics, Vol.7, No.1, 2024; 270 Views, 74 PDF Downloads

This paper summarizes the process of metal matrix composites from pressure infiltration preparation to pressure ultrasonic assisted infiltration to pressure solvent assisted infiltration. The advantages of preparing metal matrix composites by pressure infiltration alone are low cost and convenient for mass production. However, the equipment and process requirements are too high, and the quality of composite materials can not be guaranteed. Because of the high pressure of ultrasound, ultrasonic infiltration has become an auxiliary physical method for the preparation of metal matrix composites by pressure infiltration. But this method tends to damage the fibers. Therefore, the fibers need to be coated. The coating on the fiber surface is divided into metal coating and non-metal coating. Some people mixed SiC particles or whiskers in continuous carbon fibers to prepare aluminum alloy composite materials, forming a hybrid assisted infiltration method. Later, people began to pay attention to the flux-assisted role of pressure infiltration. Therefore, solvent-assisted infiltration of fiber-reinforced metal matrix composites has become an important research field.