Effect of shot peening on microstructure,nanocrystallization and microhardness of Ti-10V-2Fe-3Al alloy surface

Severe plastic deformation of Ti-10V-2Fe-3Al alloy in the surface region was caused by shot peening at air pressure of 0.6 MPa with processing time ranging from 1 to 45 min.The results showed that the thickness of surface deformation layer was proportio nal to the processing time,the microhardness of the shot-peened surface in creased from 280 to 385 HV,and the depth of highly hardening layers arrived at 200μm.It was worth noting that a grain size gradient from nanocrystalline on the surface toward coarse grain in the matrix was obtained during the shot peening process and the minimum grain size in the top surface after shot peening was about 100-200 nm.

Mechanical properties of Fe-based amorphous–crystalline composite: a molecular dynamics simulation and experimental study

A new Fe-based amorphous–crystalline composite without non-metallic elements, Fe_(55)Cr_(15)Mo_(15)Ni_(10)W_(5), was prepared by melt-spinning. The formation ability and structure information were investigated by X-ray diffractometer(XRD), energy-dispersive spectrometer(EDS) and scanning electron microscope(SEM). The mechanical properties of the amorphous–crystalline composite were investigated by nanoindentation. A molecular dynamics simulation study was performed to simulate the formation of Fe_(55)Cr_(15)Mo_(15)Ni_(10)W_(5) amorphous alloy. The mechanical properties were obtained by compression simulations simultaneously. The results indicate that the Fe_(55)Cr_(15)Mo_(15)Ni_(10)W_(5) ribbon is an amorphous–crystalline composite structure with good ductility, and the hardness of the amorphous–crystalline composite is about 75%higher than that of master ingot. The simulation mechanical properties are in good agreement with the results of nanoindentation at the nanoscale.