Effects Of Additional Element On The Glass Forming Ability And Mechanical Properties Of Bulk Zr-based Amorphous Alloys

The two main aspects involved in the work.The first is to invest the effect of the added elements on the Zr-based amorphous forming ability and mechanical properties. Basing on the work of predecessors and statistical summary, the Ti, Fe, Y elements were added to the Zr65Cu17.5Ni10Al7.5 five-alloy systems by the means of copper mold suction-casting, bulk amorphous alloys and amorphous composites were successfully prepared. The second is to study the glass forming ability, the region involved nearby the inter-metallic compound, and the inter-metallic compounds, eutectic compounds, amorphous material were successfully manufactured via the process of copper mold casting process blowing.The phase composition of materials, GFA, thermal stability, mechanical properties and fracture surface were examined by the X-ray diffraction (XRD), differential scanning measuring instrument (DSC), WDW-100J pressure testing machine, scanning electron microscopy (SEM), etc.We designed chemical formula of Zr(65-x)Ti(Fe/Y)xCu17.5Ni10Al7.5 as the alloy formula, The 3mm alloy specimen bar was prepared by copper mold cast. The change of performance of the system was investigated as the Zr element was replaced by the elements of Ti, Fe, Y.The results indicated that the alloy formula of Zr63Cu17.5Ni10Al7.5Fe2, Zr63Cu17.5Ni10Al7.5Y2, Zr62C17.5Ni10Al7.5Ti3, Zr60Cu17.5Ni10Al7.5Ti5 were pure amorphous structure, but the other alloys are amorphous composite constituted by the crystalline phase and amorphous phase.The introduction of element of Fe and Ti can significantly improve the mechanical properties of the original alloy, the breaking strength can achieve 2338Mpa as the Fe content is only 2%, and the plastic of alloy system can be raised after the Ti element was added, its plastic strain can reach 3.1% as the Ti content is 1%.In the research of the glass forming ability, we find that theΔTx and Trg were (ΔTx=69.1,Trg=0.5748),(ΔTx=68K,Trg=0.5990),(ΔTx=58K, Trg=0.6050) separately, as the element of Y and Fe up to 2%, and Ti up to 3% of Alloy system, which have shown a strong glass forming ability and thermal stability.After systematic study to the binary metallic glass forming region, the binary alloys of Zr41Cu59, Zr67Ni33, Zr49.5Ni50.5,Zr67Co33, Zr50Co50 were chosen as goals of the experiment, these components deviation from inter-metallic region, which provides the conditions for the phase composition in different regions.The results show that Zr41Cu59 lied in the junction of super-wcooled liquid in Gibbs free energy minimum and eutectic reaction; Zr49.5Ni50.5 located at the eutectic reaction zone; the compositions of Zr67Ni33, Zr67Co33,Zr50Co50 appeared where the Gibbs free energy of inter-metallic is lowest...