Characterization of Micro-Indentation Creep in β-Sn Single Crystals at Elevated Temperatures
Characterization of Micro-Indentation Creep in β-Sn Single Crystals at Elevated Temperatures
复制标题
高温下 β-Sn 单晶微压痕蠕变的表征
DOI：
10.2320/jinstmet1952.63.6_760
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发表时间：
1999
影响因子：
--
通讯作者：
M. Otsuka
中科院分区：
文献类型：
--
作者：
M. Fujiwara;M. Otsuka
This study is being conducted to determine whether the indentation creep test produces results equivalent to those of the conventional unidirectional creep tests in the dislocation creep regime． A hot−hardness tester is used to obtain information on the time dependent flow， or indentation creep， of the material beneath the indenter． When aconical indenter is pressed into the（110）plane of aβ一Sn single crystal， the deformation in the（001）Plane just under the indenter can be regarded approximately as an in−plane strain problem． Moir6 analysis of strain reveals that the plastic region in the（001）plane beneath the indenter extends while maintaining geometrical self− sinlilarity as indentation proceeds． Observation via the etch−hillock technique also gives the same result． These findings for self−similar indentation Iead to a constitutive equation from which the power law creep exponen惚and activation energy for creep（l can be derived． The values Q andηvary at a temperature of O。81Tm（％：melting point of tin）．At low temperatures ranging from O．60Tm to O。81コ㌔， the value of Q，44 kJ／mol， so obtained is comparable to the activation energy for pipe diffusion and the％一value is 75． At high temperatures of O，81Tm〜 0．92冗n，the value of Q，107 kJ／mo1， corresponds to the activation energy for lattice diffusion and theπ一value is 5，4． These values indicate that there are two parallel rate−controlling processes taking place simultaneously in the creep ofβ一Sn。 The results obtained using creep indentation are in approximate agreelnent with the conventional creep test results， drawn from a number of sources．