摘要
根据金属材料表面由于塑性损伤引起激光衍射谱的变化特征,受损材料声速、密度和弹性常数等的变化导致超声速的改变,用衍射光强比K和超声速C的变化定义了损伤变量D(K)和D(C);对LD10锻铝和40CrNiMoA合金钢材料的塑性损伤进行了检测,讨论了D(K)与D(C)的关系;并对LD10材料的表面粗糙度R_a、扫描电镜下表面微裂纹的长度B、宽度L、解理区内单位面积的空洞数n进行了测量,探讨了它们与两种损伤变量间的关系。
It is practicable to detect plastic damage by means of the techniques of laser diffraction and ultrasonic. The damage variables D(K) and D(C) are defined by diffraction spectrum intensity ratio K are ultrasonic speed C. The plastic damage of two materials, LD10 aluminum alloy and 40CrNiMoA steel, were deteced by two methods. The result show that these methods possess many advantages, such as simple equipment, easy detection, sensitive reaction, nonfailure etc. D(K) and D(C) increase monotonically with the accumulation of plastic strain ε_p. In the fore stage of this damage D(K) is sensitive to damage. D(C) is sensitive in the later stage. The statistic relation between D(K) and D(C) is D(K)=Ae^(b/D(C))+d. There is a approximate linear relationship between the roughness R_a of the surface, the cavity number n of unit area in cleavage region and the plastic strain ε_p. The definite regularity is existence among the length L, breadth B of surface microcrack by damage or roughness R_a of the surface and D(K) or D(C). These studying results can be as the basis of quasi-microscope for macro-detection of plastic damage.
出处
《机械强度》
CAS
CSCD
北大核心
1993年第1期6-10,23,共6页
Journal of Mechanical Strength
