针对镁合金材料早期力学性能退化问题,研究发展了一套可靠的非线性超声系数的测量实验系统,利用该系统测量了AZ31镁合金拉伸和疲劳试件的超声非线性系数。实验结果表明,在拉伸试件进入塑性应变阶段,疲劳试件在疲劳寿命的55%左右之前,超声非线性系数对镁合金材料力学性能退化具有很高的灵敏度。同时利用光学显微镜对拉伸试件的位错滑移带进行了原位微观观察,位错滑移带在塑性阶段随加载应力增大而增多。宏观力学、非线性超声检测和微观观察实验结果表明超声非线性系数作为宏观和微观的桥梁可以表征材料的早期力学性能退化情况。另外在中低周疲劳范围内,加载应力的大小以及拉-拉和拉-压疲劳模式的变化对实验结果没有明显的影响。
Abstract
Toward the problem of the metal material early degradation of mechanical properties,this research developed a robust experimental procedure.Using this system,ultrasonic nonlinearity parameters of AZ31magnesium monotonic load and fatigue samples were measured.The experimental results show that there is a significant increase inβlinked to magnesium mechanical performance degradation,into plastic deformation stage and before the fatigue life of 55%.Monotonic load sample was observed by optical microscopy in the same place,dislocation slip bands increase with stress.Macro-mechanics,nonlinear ultrasonic testing and microscopic observation results show that ultrasonic nonlinearity parameters as a bridge between micro and macro can characterize the mechanical properties of early degradation.However,in the context of low-cycle fatigue,changes of loading stress and the fatigue model with tension-tension fatigue and tension-compression fatigue had no significant effect to the experimental results.
关键词
非线性超声 /
AZ31镁合金 /
力学性能退化 /
微观观察
{{custom_keyword}} /
Key words
nonlinear ultrasonic /
AZ31magnesium /
mechanical performan /
observation of micro
{{custom_keyword}} /
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
税国双,汪越胜,JIANMIN QU,et al.利用直接激发Raylcigh表面波的方法测量材料的声学非线性系数[J].声学学报,2008,33(4):378-384.
CANTRELL J H.Substructural organization,dislocation plasticity and harmonic generation in cyclically stressed wavy slip metals[J].Proc R Soc Lond A,2004:316-322.
SZILARD J.Ultrasonic testing:non-conventional testing techniques[J].John Wiley Sons Ltd,1982.
N AGY P B.Fatigue damage assessment by nonlinear ultrasonic materials characterization[J].Ultrasonics,1998,36:375-381.
JORDAN P M.Finite amplitude acoustic traveling waves in a fluid that saturates a porous medium:Acceleration wave formation[J].Physics Letters A,2006,355(3):216-221.
JHANG Kyung-Young.Nonlinear ultrasonic techniques for nondestructive assessment of micro damage in material:a review.International journal of precision engineering and manufacturing,2009,10(1):123-135.
CANTRELL J H,YOST W T.Nonlinear ultrasonic characterization of fatigue microstructures[J].Int.J.Fatigue,2001,23:S487-S490
BUCK O,ALERS G A.New techniques for detection and monitoring of fatigue damage[J].Fatigue and microstructure.American Society for Metals,1979:101-147.
KIM J Y,JACOBS L J,QU J,et al.Experimental characterization of fatigue damage in a nickel-base superalloy using nonlinear ultrasonic waves[J].Journal of the Aconstic Society of America,2006,120(3):1266-1273.
SHUI Guoshuang,KIM Jim-Yeon,QU Jianmin,et al.Anew technique for measuring the acoustic nonlinearity of materials using Rayleigh waves[J].NDTE International 2008,41(1):326-329.
徐从元,姜文华.疲劳金属材料非线性声学特性的试验研究[J].南京大学学报,2000,36(3):328-335.
税国双,汪越胜,曲建民.材料力学性能退化的超声无损检测与评价[J].力学进展,2005,35(1):52-68.
SOHN K Y,JONES J W,BERKMORTEL J,et al.Creep and Bolt Load Retention Behavior of Die Cast Magnesium Alloys for High Temperature Application[C].SAE Technical Paper Series,20002-012-1120,Warrendale,PA,2000.
胡艳辉,李建国,谭敦强,等.细晶AZ31镁合金高温压缩变形行为研究[J].航空材料学报,2010,30(1):36-40.
BREAZEALE M A,PHILIP Jacob.Determination of Third ordcr Elastic Constants from Ultrasonic Harmonic Generation Measurements[C].Physical Acoustics,Vol.17,Academic Press,INC.1984.
CANTRELL J H.Crystalline structure and symmetry dependence of acoustic nonlinearity parameters[J].J Appl Phys,1994,76(6):3372-3380.
Hurley D C,Fortunko C M.Determination of the nonlinear ultrasonic parameter βusing a Michelson interferometer[J].Meas Sci Technol,1997,8:634-642.
YOST W T,CANTRELL J H.Materials characterization using acoustic nonlinearity parameters and harmonic generation.Rev.QNDE,1990;9B:1669-1676
{{custom_fnGroup.title_cn}}
脚注
{{custom_fn.content}}
基金
北京市教委科技计划重点资助项目(KZ200810005001);国家自然科学基金资助项目(10772008)
{{custom_fund}}
PDF(1467 KB)
