Thermomechanical and isothermal fatigue behavior of bare and coated superalloys

被引:21
作者
Kadioglu, Y [1 ]
Sehitoglu, H [1 ]
机构
[1] UNIV ILLINOIS,DEPT ENGN MECH,URBANA,IL 61801
来源
JOURNAL OF ENGINEERING MATERIALS AND TECHNOLOGY-TRANSACTIONS OF THE ASME | 1996年 / 118卷 / 01期
关键词
D O I
10.1115/1.2805939
中图分类号
TH [机械、仪表工业];
学科分类号
0802 ;
摘要
Thermomechanical fatigue (TMF) and isothermal fatigue (IF) experiments were performed on bare Mar-M246 as well as bare and coated Mar-M247 nickel based superalloys at strain ranges from 0.335 to 1 percent. The experiments were conducted in air, through a temperature range of 500 to 1038 degrees C at a constant strain rate of 5.0 x 10(-5) s(-1). Due to the coarse-grained structure of Mar-M246, TMF lives scattered considerably under low strain range conditions. Electron microscopy studies show that significant surface oxidation and gamma prime, gamma', depleted zones occur for Mar-M246 under these conditions. In the surface grain, where the change in gamma' morphology is most pronounced gamma' rafted along axes approximate to +/-45 deg from the loading axis. The influence of a protective coating on the IF and TMF lives of Mar-M247 was also examined. Results indicate that the coating does nor significantly affect the fatigue lives of Mar-M247. The oxidation behavior of bare and coated Mar-M247 was investigated via X-ray microprobe and Auger Spectroscopy. Through these analyses, it is evident that the coating was completely degraded when exposed to the test environment for a long time. In both Mar-M246 and Mar-M247, in-phase thermomechanical fatigue (TMF IF) loading resulted in intergranular cracking. TMF IP loading promoted multiple cracks at the coating/substrate interface of coated Mar-M247. Finally, Eshelby techniques were used to calculate stress distributions in the vicinity of a surface oxide and second-phase particle at the coating/substrate interface.
引用
收藏
页码:94 / 102
页数:9
相关论文
共 55 条
[1]  
[Anonymous], SUPERALLOY
[2]   LOW-CYCLE FATIGUE OF RENE-77 AT ELEVATED-TEMPERATURES [J].
ANTOLOVICH, SD ;
ROSA, E ;
PINEAU, A .
MATERIALS SCIENCE AND ENGINEERING, 1981, 47 (01) :47-57
[3]   LOW-CYCLE FATIGUE BEHAVIOR OF RENE 80 AT ELEVATED-TEMPERATURE [J].
ANTOLOVICH, SD ;
LIU, S ;
BAUR, R .
METALLURGICAL TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE, 1981, 12 (03) :473-481
[4]  
ANTOLOVICH SD, 1980, SUPERALLOYS 1980, P605
[5]  
AU P, 1990, SURFACE MODIFICATION, V3, P729
[6]  
BAIN KR, 1985, AIAA SAE ASME ASEE 2, P1
[7]  
BARBER ME, COMMUNICATION
[8]  
Bill R., 1984, TP2280 NASA
[9]   THERMOMECHANICAL FATIGUE OF MAR-M247 .1. EXPERIMENTS [J].
BOISMIER, DA ;
SEHITOGLU, H .
JOURNAL OF ENGINEERING MATERIALS AND TECHNOLOGY-TRANSACTIONS OF THE ASME, 1990, 112 (01) :68-79
[10]  
Boismier DA, 1988, THESIS U ILLINOIS UR