Ion-beam-assisted fabrication and manipulation of metallic nanowires

Metallic nanowires (NWs) are the key performers for future micro/nanodevices. The controlled manoeuvring and integration of such nanoscale entities are essential requirements. Presented is a discussion of a fabrication approach that combines chemical etching and ion beam milling to fabricate metallic NWs. The shape modification of the metallic NWs using ion beam irradiation (bending towards the ion beam side) is investigated. The bending effect of the NWs is observed to be instantaneous and permanent. The ion beam-assisted shape manoeuvre of the metallic structures is studied in the light of ion-induced vacancy formation and reconfiguration of the damaged layers. The manipulation method can be used for fabricating structures of desired shapes and aligning structures at a large scale. The controlled bending method of the metallic NWs also provides an understanding of the strain formation process in nanoscale metals

Modelling of retained austenite in carburized layers

In this paper, modelling of the phase composition of the carburized case produced on steel alloys containing chromium, manganese and nickel will be discussed. In particular, the effect of steel composition on the amount of retained austenite and carbide structure will be discussed. These microstrucures were selected because they exhibit the greatest influence on the correlation between structure and properties of hardened carburized case. The thermal process largely influences the formation of carbides quantity of residual austenite in structure of hardened carburized elements. Properties evaluated include: hardness, micro-hardness, and impact resistance. The model can be applied to carburized 20H (20Cr4), 15HN (17CrNi6-6) and 16HG (16MNCr5) steel although data for 20H (20Cr4) steel is provided here

Modelling of phase transformations and hardening of carbonitrided steels

There are a variety of opinions regarding the influence of retained austenite and carbides on the properties exhibited by carbonitrided steels. In this paper, the development of a model marking relationship between phase composition, and properties of hardened carbonitrided steel has been presented. A summary of the impact of structure on properties is provided in Table 1. In the study reported here, the impact of thermal processing conditions on retained austenite and carbides was examined for carbonitrided and hardened 20 (C22), 20H (20Cr4), 15HN (17CrNi6-6) and 16HG (16MnCr5) steels. The models that are reported were experimentally validated. In particular, the results obtained for structure with respect to hardness and abrasive wear resistance were discussed for carbonitrided and hardened 20H (20Cr4) steel