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One of the most important parameter in cutting is the cutting force and the ratio of the components of the force. The ratio of the main force component and the chip's cross-section is the so-called specific cutting force. The specific cutting force is closely linked to the mechanical properties of the material such as the tensile strength and hardness. This paper discusses the dependence of the specific cutting force on the microstructure of the material. Two kind of specimens are examined which have the same chemical composition and hardness but different microstructure -due to different heat treatment.

Finite element modelling is a modern and efficient way to perform stress-strain analyses on both simple components and complex structures. If the material properties are properly set, the software can also model the deformation of parts. A very important criterion of accurate finite element calculations is an appropriate material model. The stress–strain function recorded during the tensile testing of standard specimens shows that stress is not constant during deformation and so it can be specified with a function in finite element software. Often, in finite element modelling, a bilinear model is used to simplify this function. The aim of this paper is to show the difference between the bilinear model, the multilinear model (the model split into several sections the stress-strain curve) and the real function in the analysis of deformation in hardness testing. We also analyse the minimum density of meshing which still provides acceptable accuracy in hardness testing calculations.

It is long been known that composite materials are made from two or more constituent materials. Thereby, we can create material structures with much better mechanical properties as the constituents have. This paper shows the creating process and research results of an aluminium composite reinforced with metal hollow spheres. It also includes an analysis about the problems of cutting this kind of materials.