Effects of Dodecaboride-Forming Metals on the Properties of Superhard Tungsten Tetraboride

被引：25

作者：

Akopov, Georgiy ^{[1
]}

Yeung, Michael T. ^{[2
]}

Roh, Inwhan ^{[1
]}

Sobell, Zachary C. ^{[1
]}

Yin, Hang ^{[1
]}

Mak, Wai H. ^{[1
]}

Khan, Saeed I. ^{[1
]}

Kaner, Richard B. ^{[1
,3
,4
]}

机构：

[1] Univ Calif Los Angeles, Dept Chem & Biochem, Los Angeles, CA 90095 USA

[2] Northwestern Univ, Dept Chem, 2145 Sheridan Rd, Evanston, IL 60208 USA

[3] Univ Calif Los Angeles, Dept Mat Sci & Engn, Los Angeles, CA 90095 USA

[4] Univ Calif Los Angeles, Calif NanoSyst Inst, Los Angeles, CA 90095 USA

来源：

CHEMISTRY OF MATERIALS | 2018年 / 30卷 / 10期

基金：

美国国家科学基金会;

关键词：

HIGH-PRESSURE SYNTHESES; AMBIENT-PRESSURE; BORON; SYSTEM; TEXTURE; STABILIZATION; SCANDIUM; BORIDES; HFB12; GD;

D O I：

10.1021/acs.chemmater.8b01464

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Tungsten tetraboride alloys with Y, Sc, Gd, Tb, Dy, Ho, and Er were prepared by arc-melting and investigated for their thermal stability and mechanical properties. The phase composition and purity were confirmed by powder X-ray diffraction (PXRD) and energy dispersive X-ray spectroscopy (EDS). In all cases, except for Sc, a change to a "dendritic" morphology was observed. For alloys with Sc, the metal boride and boron grains became smaller; however, no patterning was observed. This shows that tuning the composition of the alloys of WB4 with transition metals and lanthanides results in a modification of the morphology leading to patterning and smaller grains that enhance mechanical and thermal properties. For alloys of WB4 with Y, Sc, Gd, Dy, Tb, Ho, and Er, an increase in hardness to 50.2 +/- 2.4, 48.9 +/- 2.S, 48.0 +/- 2.1, 46.3 +/- 2.6, 48.5 +/- 2.3, 46.4 +/- 3.4, and 47.2 +/- 2.9 GPa at low load, respectively, compared to 41.2 +/- 1.4 GPa for WB4 is observed. Moreover, the alloys of WB4 with Y, Sc, and Gd showed an increase in oxidation resistance from 450 degrees C for WB4 to similar to 470, similar to 525, and 465 degrees C, respectively.

引用

页码：3559 / 3570

页数：12

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