KNOOP MICROHARDNESS ANISOTROPY OF SINGLE-CRYSTAL LAB6

被引:71
作者
LI, H
BRADT, RC
机构
[1] Mackay School of Mines, University of Nevada, Reno
来源
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING | 1991年 / 142卷 / 01期
关键词
D O I
10.1016/0921-5093(91)90753-A
中图分类号
TB3 [工程材料学];
学科分类号
0805 ; 080502 ;
摘要
Knoop microhardness profiles were determined for lanthanum hexaboride (LaB6) on the (100), (110) and (111) planes for indentation test loads from 50 to 300 gf. These profiles were analyzed with respect to possible slip systems to explain the Knoop microhardness anistropy by applying the effective resolved shear stress concept advanced by Brookes and coworkers. As the results of this study, the predicted slip systems for LaB6 are {100}<011BAR>, {110}<111BAR> and {111}<110BAR>. The load dependence of the microhardness was initially addressed in terms of the classical Meyer's law P = Ad(n) for which the two parameters A and n were observed to be related. The peculiar dimensionality of the classical Meyer's law coefficient A was addressed by applying the concepts of a load-independent "true" microhardness, critical indentation load and characteristic indentation size. Subsequently the development of a normalized Meyer's law was directly demonstrated, yielding P = 2P(c)/n(d/d0*)n where P(c) is a critical test load indicative of the region where hardness is independent of the indentation test load and d0* is a characteristic indentation dimension, below which the indentation size effect is significant. It is suggested that this normalized Meyer's law may have universal applicability to different hardness tests and materials.
引用
收藏
页码:51 / 61
页数:11
相关论文
共 30 条
[1]  
AKIMUNE Y, 1987, J AM CERAM SOC, V70, pC84, DOI 10.1111/j.1151-2916.1987.tb04994.x
[2]  
AKIMUNE Y, 1985, THESIS U WASHINGTON
[3]   HARDNESS ANISOTROPY OF INP [J].
BRASEN, D .
JOURNAL OF MATERIALS SCIENCE, 1976, 11 (05) :791-793
[4]  
Brookes C.A., 1973, SCI HARDNESS TESTING, P199
[5]  
Brookes C.R., 1983, SCI HARD MATERIALS, P181
[6]   ANISOTROPY IN HARDNESS OF SINGLE CRYSTALS [J].
BROOKES, CA ;
ONEILL, JB ;
REDFERN, BAW .
PROCEEDINGS OF THE ROYAL SOCIETY OF LONDON SERIES A-MATHEMATICAL AND PHYSICAL SCIENCES, 1971, 322 (1548) :73-&
[7]  
BROOKES CA, 1971, 1971 P IR STEEL I C, P29
[8]   HARDNESS ANISOTROPY OF SRF2, BAF2, NACL AND AGCL CRYSTALS [J].
CHIN, GY ;
GREEN, ML ;
VANUITER.LG ;
HARGREAVES, WA .
JOURNAL OF MATERIALS SCIENCE, 1973, 8 (10) :1421-1425
[9]   HARDNESS TESTING OF CERAMIC MATERIALS [J].
CLINTON, DJ ;
MORRELL, R .
MATERIALS CHEMISTRY AND PHYSICS, 1987, 17 (05) :461-473
[10]  
CLINTON DJ, 1986, P BR CERAM SOC, V34, P113