基于激光散斑法評估金屬表面狀態(tài)

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摘 要
散斑干涉法是 70 年代發(fā)展起來的一種方法，它具有非接觸和無損的優(yōu)點，可用于實物測量。由于測量靈敏度高、設備簡單, 根據(jù)所采用的分析技術可以給出逐點和全場信息, 因而近年來得到了廣泛應用，然而激光散斑技術在表面分析領域中尚未有全面深入的研究，為了追求更簡單的評估金屬表面狀態(tài)的方法，將研究目光投向了激光散斑技術，提出了基于激光散斑法評估金屬表面狀態(tài)的研究。
通過對激光散斑技術應用的一些比較成熟的領域和現(xiàn)今的一些表面分析技術詳細的了解，基于前人的研究啟發(fā)提出了評估表面狀態(tài)的標尺猜想，給出了新標尺的詳細內(nèi)容和設計到的參數(shù)，并設計了對比實驗，對猜想進行了實驗論證。由于反射光的強度取決于表面的幾何微觀結構和顏色，所以表面的任何變化將導致不同的散斑圖像。在此基礎上，分析激光散斑圖像的參數(shù)，結合表面粗糙度，綜合評定金屬表面狀態(tài)。研究以激光清洗的涂漆金屬表面為實驗樣品，基于激光散斑法評估樣品的激光清洗部分的表面狀態(tài)為核心展開。樣品的制作、實驗設備的搭建、實驗結果的分析，合理的規(guī)劃實驗線路，使得實驗部分有條不紊。本次研究設計到了一款圖像分析軟件，為了得到所需的散斑圖像參數(shù)，選擇matlab軟件分析處理實驗獲得的散斑圖像。
本次研究為探究性研究，樣品的制作、實驗設備的局限、散斑圖像的獲取、參數(shù)的分析都直接關系到實驗的結果。研究發(fā)現(xiàn)不同的金屬表面獲得的激光散斑圖像明顯不同，
通過散斑圖像的分析結果也能發(fā)現(xiàn)相應的差異。相同粗糙度表面獲得的散斑圖像及其散斑參數(shù)的分析也不盡相同，但只在一個小范圍內(nèi)波動，不排除實驗誤差的影響，雖不能盲目的說明實驗證實了自己的理論，但總的實驗可以說明，當分析獲得的散斑圖像之間產(chǎn)生了較為明顯的波動時，我們可以斷定與之相應的表面狀態(tài)有差異，當其散斑結果只是波動在小范圍內(nèi)，我們可以視作其對應的金屬表面狀態(tài)接近或者相等。基于激光散斑法評估金屬表面狀態(tài)的研究為激光加工的在線檢測等技術提供有力支持。
關鍵詞：激光散斑 金屬 表面狀態(tài) 散斑分析


State eva luation of the metal surface based on the laser speckle method
Abstract
Speckle interferometry is a method developed in the 70 s, it has the advantages of non-contact and non-destructive, can be used in the actual measurement. Because of high sensitivity, simple equipment, according to the analysis technology can be adopted by the given point and the information, which has wide application, however, in the field of laser speckle techniques on surface analysis has not yet have comprehensive in-depth research, in order to pursue more simple method of eva luating metal surface state, will study looking at the laser speckle technique, is presented based on the laser speckle method eva luating the state of the metal surface.
By means of laser speckle technique used some of the more mature areas and present some detailed understanding surface analysis technology, the eva luation of surface state was developed based on the predecessors' research inspired the scale of conjecture, gives a new scale to the detailed content and design parameters, and designed a contrast experiment, has carried on the experiment to guess. Due to the intensity of the reflected light depends on the geometry of the surface microscopic structure and color, so any changes will lead to different on the surface of the speckle image. On this basis, the analysis of the parameters of laser speckle images, combining with the surface roughness, the comprehensive eva luation of metal surface state. Research to painted metal surface laser cleaning as experimental samples, based on laser speckle method to eva luate the sample state of laser cleaning the surface of the part as the core. Samples of the production, the construction of the experimental equipment, the results of analysis, reasonable planning experiment circuit, makes the experimental section in an orderly way. The study design to a image analysis software, in order to get the required speckle image parameters, select matlab software analysis experiment of speckle image processing.
The study for exploratory research, sample production, the limitations of experimental equipment, speckle image acquisition, the analysis of the parameters are directly related to the results of the experiment. The study found that the different metal surface laser speckle images are obviously different, through the analysis of speckle image results can also be found the corresponding difference. The same surface roughness obtained by speckle image and the speckle parameter analysis also is not the same, but only in a small scale fluctuation, don't rule out the influence of experimental error, not to blindly explanation of the experiment confirmed his theory, but the total can experiment shows that when analyzing the speckle image between the more obvious fluctuations, we can conclude that with the corresponding surface state of difference, only when the speckle fluctuations on a small scale, we can be seen as the state of the corresponding metal surface close to or equal. Metal surface is assessed based on laser speckle method of research for the on-line measurement of laser processing technology to provide strong support.

Keywords: laser speckle metal Surface sta..