Application of erosion dimensional treatment methods for creation transversal fasteners in “metal-composite” joints

Abstract

At design of high-loaded units of engineering objects, especially such as articles of aero-space engineering, the problem of creation of reliable joints between metal and composite articles having predefined strength and ability to fulfill given functions appears. Development and grounding of selection of structural-manufacturing solutions of “metal-composite” joints with transversal fastening elements is selected as the objective of studying. As the object for studying possible structural-manufacturing solutions of “metal-composite” joints that use transversal fastening elements which are embedded to composite and attached to metal article or produced on its surface. Three types of fastening micro-elements are considered, i.e. pyramidal monolithic, cylindrical and sheet-formed, also different technologies of fastening elements production are considered too. Mass of typical flat article with micro-pins at given load-carrying ability of “metal-composite joint” was esti-mated for above-mentioned types of micro-fasteners. Such quantitative indexes of manufacturability as labor-intensity and energy consumption of fastening elements production were considered as results of studies. Approach to comparison methods of fastening elements manufacturing is suggested. This approach is based on analysis of correspondent numerical specific indexes of labor-intensity and energy consumption. These indexes are com-pared for micro-pins which are assumed to be produced of aluminum, titanium alloys and stainless steels. Distinctive feature of suggested model of analysis is taking into consideration both main and auxiliary techno-logical operations, which influence significantly on manufacturing labor-intensity and duration. Process of classical milling with cylindrical and disc mills is compared with up-to-date methods of electro-erosion cutting with wire. Recommendations for selection shape, type and arrangement scheme of micro-fasteners on article surface and exact manufacturing process of micro-pins production at given material are formulated as conclusions.