Mechanical and tribological properties of ice-bonded abrasive polishing tools

This article covers the efforts on characterising ice-bonded abrasive polishing tool in terms of the mechanical and tribological properties such as hardness, coefficient of friction, and wear rate. These studies were attempted on the tools prepared at different temperatures ranging from −10 °C to 0 °C with a view to identify the condition suitable to prepare ice-bonded abrasive polishing tool for effective polishing of Ti–6Al–4V alloy specimen. It also presents the methods adopted to determine various properties of ice-bonded abrasive polishing tool. Hardness was estimated from the measured penetration depth of cone shape indenter into the tool, coefficient of friction was determined from the change in power drawn by the motor rotating the tool mould, and wear behaviour of tool was assessed from the melting rate of the tool determined from the change in height of ice-bonded abrasive polishing tool at different stages of polishing. From the results of this study, it is clear that ice-bonded abrasive polishing tool prepared at −4 °C has possessed sufficient hardness, coefficient of friction, and reasonable wear rate suitable for polishing of Ti–6Al–4V specimens. This article also covers the details of low-temperature coolant supply unit developed to prepare the ice-bonded abrasive polishing tool at any desired temperature between 0 °C and −40 °C and thus to maintain it for a long time. Polishing studies with such ice-bonded abrasive polishing tool showed 72% improvement in finish after 90 min of polishing of Ti–6Al–4V specimen with tool, prepared at −4 °C.

Investigation of Mechanical Properties of Unidirectional Fibrous Composite by Micro-Mechanics Model

The use of advanced composite materials reinforced with fibers is expanded in these years. The main reason for the increased use of these materials is their high strength and hardness coefficient, their density and low prices. So, the fiber-reinforced composite materials can be used in the design of structures that require high strength to weight ratio and hardness coefficient. In order to replace these materials and new applications, many research programs to study the mechanical behavior of these materials has shifted. In this paper Finite element model presented in which the fibers and matrix are modeled separately and to show a full description of the properties of the constituent components, the interface between matrix and fiber discontinuity is presented in the model With using modeling and analysis after great determination of mechanical properties of unidirectional fibrous composite single and compared with experimental results, the elastic modulus changes depending on the angle of the fibers is received . The results of this method are compared with available mathematical models.