摘要
针对30CrMnSiA合金韧窝断口复杂的表面特征,运用扫描白光干涉法检测微观形貌。系统采用Linnik结构,并通过空间频域分析算法重建断口表面三维形貌,试验中扫描行程达120μm,纵向检测精度优于5 nm,频域分析表现出很强的位相提取和噪声抑制能力。研究韧窝断口的三维Motif表征方法,提出包含深度、长度、宽度、面积、方向角和各向异性率等6参数的定义,以及基于面积和深度阈值的合并算法。考虑到韧窝三维形态的各向异性,对基于纵横比的表面微观粗糙度定义进行修正。采用3D-Motif法对试验获得的断口三维形貌进行表面纹理分割,提取韧窝个体特征参数和统计数据,其中测得断口表面微观粗糙度为0.15～0.70,从而为定量化研究材料的断裂机理提供客观依据。
In view of the complex surface properties of 30CrMnSiA dimple fracture,scanning white-light interferometry is used to measure microscopic topography.The Linnik structure is adopted in the system and the 3D image of dimple fracture is rebuilt by spatial frequency analysis.Longitudinal accuracy is better than 5 nm for a scan range of 120 μm in the experiment.The frequency-domain analysis approach exhibits strong abilities of phase extraction and noise suppression.3D-Motif method for assessing dimple fracture surface is studied,six parameters including depth,length,width,area,direction angle and anisotropy rate are defined,and combination algorithm based on area and depth threshold is proposed.Considering the anisotropy of dimple microtopography,the definition for surface micro-roughness based on aspect ratio is modified.The obtained three-dimensional surface topography is partitioned to extract both single dimple character and statistical parameters,in which the micro-roughness of the fracture surface is tested to be around 0.15～0.70,thereby providing the objective basis for quantitative study on the mechanism of fracture.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2011年第10期8-13,共6页
Journal of Mechanical Engineering
基金
航空科学基金资助项目(20085656018)
