Nanostructured laminar tungsten alloy with improved ductility by surface mechanical attrition treatment

A nanostructured laminar W-La₂O₃ alloy (WL10) with improved ductility was prepared using a surface mechanical attrition treatment (SMAT). φ1.5 mm ZrO₂ WL10 balls subjected to SMAT (called φ1.5 mm ZrO₂ ball SMATed WL10) samples possess the best surface profile and excellent integrated mechanical properties (the ductile-brittle transition temperature (DBTT) value decreases by approximately 200 °C, and the bending strength decreases by 100 Mpa). A highly dense group of laminates was detected near the surface of the φ1.5 mm ZrO₂ ball SMATed WL10 sample. The SMATed WL10 laminates were composed of a micro-grain layer, an ultrafine-grain layer and a nanosized-grain layer. The nanostructured laminar surface layer of the φ1.5 mm ZrO₂ ball SMATed WL10 sample is approximately 1-2 μm. The top surface of the WL10 plates with and without the SMAT process possesses residual compressive stress of approximately -883 MPa and -241 MPa, respectively, in the y direction and -859 MPa and -854 MPa, respectively, in the x direction. The SMAT process could be a complementary method to further improve the toughness of tungsten-based materials.