AN X-RAY STUDY OF CREEP-DEFORMATION INDUCED CHANGES OF THE LATTICE MISMATCH IN THE GAMMA-'-HARDENED MONOCRYSTALLINE NICKEL-BASE SUPERALLOY SRR-99

被引:215
作者
KUHN, HA
BIERMANN, H
UNGAR, T
MUGHRABI, H
机构
[1] EOTVOS LORAND UNIV, INST GEN PHYS, H-1445 BUDAPEST, HUNGARY
[2] UNIV ERLANGEN NURNBERG, INST WERKSTOFFWISSENSCH, LEHRSTUHL I, W-8520 ERLANGEN, GERMANY
来源
ACTA METALLURGICA ET MATERIALIA | 1991年 / 39卷 / 11期
关键词
D O I
10.1016/0956-7151(91)90095-I
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
X-ray line profile measurements were performed on monocrystalline specimens of the gamma'-hardened nickel-base superalloy SRR 99 with axes close to the [001] direction. The aim was to measure the local lattice parameters in the y-matrix and in the gamma'-particles and to obtain information on the lattice mismatch and internal stresses. For this purpose, a special high-resolution double crystal diffractometer with negligible instrumental line broadening was used. Measurements were performed on specimens in the initial state with cuboidal gamma'-particles and on creep-deformed specimens containing the so-called gamma/gamma'-raft structure. In several cases the line profiles were measured as a function of the rocking angle, and the intensity distributions were mapped in reciprocal space around the (002) and (020) Bragg reflections. In the undeformed state these intensity distributions indicate that the local lattice parameter varies spatially in the gamma-phase. The line profiles of specimens in the initial state were asymmetric. A remarkable result obtained on creep-deformed specimens was that, whereas the asymmetry of the (020) line profiles was enhanced to the extent that a hump or a second peak appeared, the asymmetry of the (002) line profiles was reversed in sign. A quantitative evaluation yielded mean values of the constrained lattice mismatch which, in the case of creep-deformed specimens, differ significantly for the (001) and (010) lattice plane spacings. It is concluded that the orientation-dependent lattice spacings represent a triaxial state of residual stress which has its origin in the superposition of the originally present coherency stresses and the deformation-induced internal stresses. All observed features could be explained in detail in terms of a composite model of plastic deformation, which takes into account the dislocation networks deposited at the gamma/gamma'-interfaces during deformation.
引用
收藏
页码:2783 / 2794
页数:12
相关论文
共 32 条
[1]  
BIERMANN H, 1991, 9TH P INT C STRENGTH, V1, P421
[2]   ON THE EFFECTS OF HEAT-TREATMENTS ON THE CREEP-BEHAVIOR OF A SINGLE-CRYSTAL SUPERALLOY [J].
CARON, P ;
HENDERSON, PJ ;
KHAN, T ;
MCLEAN, M .
SCRIPTA METALLURGICA, 1986, 20 (06) :875-880
[3]   INTERNAL-STRESSES DUE TO DISLOCATION WALLS AROUND 2ND PHASE PARTICLES [J].
CARRY, C ;
DERMARKAR, S ;
STRUDEL, JL ;
WONSIEWICZ, BC .
METALLURGICAL TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE, 1979, 10 (07) :855-860
[4]   THE APPLICATION OF CONVERGENT-BEAM ELECTRON-DIFFRACTION TO THE DETECTION OF SMALL SYMMETRY CHANGES ACCOMPANYING PHASE-TRANSFORMATIONS .1. GENERAL AND METHODS [J].
ECOB, RC ;
SHAW, MP ;
PORTER, AJ ;
RALPH, B .
PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES, 1981, 44 (05) :1117-1133
[5]   THE MEASUREMENT OF PRECIPITATE MATRIX LATTICE MISMATCH IN NICKEL-BASE SUPER-ALLOYS [J].
ECOB, RC ;
RICKS, RA ;
PORTER, AJ .
SCRIPTA METALLURGICA, 1982, 16 (09) :1085-1090
[6]   CORRELATION OF MICROSTRUCTURE AND CREEP STAGES IN THE (100) ORIENTED SUPERALLOY SRR-99 AT 1253-K [J].
FELLERKNIEPMEIER, M ;
LINK, T .
METALLURGICAL TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE, 1989, 20 (07) :1233-1238
[7]   THE INFLUENCE OF COHERENCY STRAIN ON THE ELEVATED-TEMPERATURE TENSILE BEHAVIOR OF NI-15CR-AL-TI-MO ALLOYS [J].
GROSE, DA ;
ANSELL, GS .
METALLURGICAL TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE, 1981, 12 (09) :1631-1645
[8]  
HAMMER J, 1990, THESIS U ERLANGENNUR
[9]  
Hammer J, 1990, ADV MATER PROCESS, V1, P445
[10]  
KUHN HA, 1987, THESIS U ERLANGEN NU