A laser sintered layer of metal matrix consisting of 0D, 1D and 2D nanomaterials and its mechanical behaviors

Dong Lin, Purdue University

Abstract

Metal matrix nanocomposites (MMNCs), integrated nanomaterials into a metal matrix, are designed to improve the corrosion, fatigue life, creep life, etc. Laser sintering (LS) is one of the methods to integrate nanomaterials into metal matrix. In this study, LS is proposed in order to integrate 0D, 1D and 2D nanomaterials into metal matrix to strengthen the metal matrix. Iron was chosen as the substrate; however, this technique can be also applied to sinter nanomaterials into other metal matrices, such as copper, nickel, titanium, etc. The temperature field during the laser sintering process and was simulated by Comsol multiphysics. The SEM, TEM and XRD results show that nanomaterials were separated well and survived after laser sintering. A theoretical study of strengthening iron matrix by 2D materials after laser sintering was presented in this thesis. The TEM result of the interface with graphene oxide (GO) shows that iron carbide was generated. Fatigue life was improved by adding 2D nanomaterials into the iron matrix. LS plus LSP on 0D (TiN nanoparticles) integrated nanocomposites was studied not only by a theoretical study but also experimental investigation. Higher surface hardness and compressive residual stress were achieved by this technique. The thermal stability of surface hardness and compressive residual stress were also increased, which is beneficial for improving the resistance for crack initiation and crack propagation. Fatigue life after LS plus LSP is higher than LSP and as received samples.

Degree

Ph.D.

Advisors

Cheng, Purdue University.

Subject Area

Engineering|Mechanical engineering

COinS