Qingzhi Yan

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

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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). φ1.5u2009mm ZrO2 WL10 balls subjected to SMAT (called φ1.5u2009mm 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 200u2009°C, and the bending strength decreases by 100u2009Mpa). A highly dense group of laminates was detected near the surface of the φ1.5u2009mm 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 φ1.5u2009mm ZrO2 ball SMATed WL10 sample is approximately 1–2u2009μm. The top surface of the WL10 plates with and without the SMAT process possesses residual compressive stress of approximately −883u2009MPa and −241u2009MPa, respectively, in the y direction and −859u2009MPa and −854u2009MPa, respectively, in the x direction. The SMAT process could be a complementary method to further improve the toughness of tungsten-based materials.

Observation of intermediate template directed SiC nanowire growth in Si-C-N systems.

SiC nanowires (NWs) are commonly prepared in a Si-C-N system, but its formation mechanism is not fully understood. High resolution transmission electron microscopy and electron energy loss spectroscopy observation recorded the growth process of how Si(3)N(4) NWs were transformed into SiC NWs, and demonstrated the validity of an intermediate template directed SiC NW growth via carbothermal reduction of intermediate Si(3)N(4) NWs in a Si-C-N system. Based on this discovery, an intermediate-template growth mechanism of SiC NWs was proposed.