Study On The Photocatalytic Reduction Performance Of N-doped Titanium Oxide Films With Noble Metal Modification

In this paper,a systematic research was conducted on the deformation mode and its influence to the microstructure and properties of the steel wires in the process of cold drawing deformation,by using Scanning Electron(SEM),Transmission Electron Microscope(TEM),X-ray Diffraction analysis method(XRD),Electron Backscattered Diffraction(EBSD)system and related mechanical properties testing methods.The effects of single-direction/reverse-direction drawing on the microstructure,texture and dislocation configuration of low carbon steel wire were studied,and the influence of drawing mode on the deformation process of steel wire was discussed.The effect of drawing mode on the structure and properties of steel wire was studied,the results show that:1)With the increase of strain,the tensile strength of steel wire is increasing,from the initial strength of 500MPa to about 1200MPa.Low tensile strain ?<1.2,the strength of reverse-direction drawn wire is higher than that of single-direction drawn wire;high tensile strain 1.2??E?2.5,tensile strength of single-direction drawn wire is higher than reverse-direction drawn wire.2)After multi-pass drawing,the ferrite lamellar spacing is reduced and the fibrosis phenomenon occurs.Compared with the single-direction drawn wire,the structure of reverse-direction drawn wire is more elongated,and is biased toward the drawing direction overall.3)The axial residual tensile stress is introduced on the surface of the single-direction drawn steel wire.The stress increases with the increase of the strain,and the residual tensile stress reaches about 250MPa at the maximum strain.The residual compressive stress is introduced on the surface of the single-direction drawn wire,when ?=1.42,the compressive stress reaches a maximum of about-500MPa.The effect of drawing mode on the microstructure of steel wire was studied.,the results show that:1)The degree of fibrosis of single-direction wire is higher than that of reverse-direction wire,and the difference is gradually reduced with the increase of strain.2)After cold drawing deformation,the ferrite grains in the wire rotate to the direction of<110>,and the strength of the<110>fiber texture gradually increases with the increase of the strain.The texture strength of single-direction drawn steel wire is higher than that of reverse-direction drawn steel.With the increase of strain,the difference decreases from 25%to 5%.3)Low tensile strain ??1.2,the dislocation of single-direction drawn wire slender and parallel to each other,single-slip dislocations more exist;the dislocation of reverse-direction drawn wire tangled serious,multi-slip system started.High tensile strain 1.2???2.5,the dislocation of single-direction drawn wire is short and remains straight,the paralled dislocation and the neat wall of dislocation still can be observed;the dislocation of reverse-direction become shorter and bent seriously,the dislocation configuration is more complicated.