Estimating the influence of texture on the resistance and wear of bimetals

Abstract

The final goal in developing and applying all multi-layered materials, and also bimetals, in reflection to monometallic materials, is in getting better mechanical and economic features (e.g. improved wear and corrosion resistance; less specific weight; higher resistance to crack initiation; saving expensive material, etc). High possibilities for producing bimetals as a combination of different monometals goes in favour of producing new material qualities, and at the same time widening its field of application. Wide area of bimetal application requires constant development of mechanical and structural characteristics. This can be achieved by applying various regimes of cold plastic deformation, whereas the material structure gains a crystallographic texture orientation that predominantly effects material behaviour. (1,2) Influence of texture components and their characteristics to the condition of surface layers in the tested materials in cases of a given regime of cold plastic deformation is considered. Efforts were made to apply a treatment regime and produce effective texture that would enhance resistance and wear features. Hot rolled sheets of low-carbon steel were joined to brass Cu76Zn24, Cu77Zn23 and Cu78Zn22, separately. All brass specimens were deformed in rolling regimes RI and RII. Larger degrees of deformation were in case of regime RI (Id/hm  5), with a smaller number of passes, while in regime RII (ld/hm ≈ 0.7), the number of passes was larger, with a smaller deforming degree (ld -deformation zone length, hm -mean thickness of rolled sheets). A special Horta method was used to evaluate the texture on three brass alloys - surface bimetal layers (3, 4, 5, 6). Figures 1 and 2 show the distribution of texture components expressed by the phkl parameter. The changes in structure showed а finer grain for all alloys in the case of regime RII. The rise in material resistance, decrease in wear, and also uniform distribution of texture components (Fig. 2), all go in favour of regime RI as the optimal.