金屬表面粗糙度之偏振散射光量測技術

Polarized light scattering measurement of metal surface roughness

王凱平(Kai-Ping Wang)

指導教授 ： 劉承揚

淡江大學/工學院/機械與機電工程學系碩士班/碩士(2012年)

https://doi.org/10.6846/TKU.2012.00018

摘要

本論文主要是應用偏振散射光量測技術來分析金屬表面粗糙度，取代傳統的接觸式量測，可提高粗糙度量測的速度及精確性。本論文所設計的系統為非接觸式量測，所以不會傷及工件表面且具有便利性佳及設備價格低廉等優點。量測系統使用高準直性之綠光雷射照射金屬表面，以CCD攝影機量測表面粗糙度散射光分佈，藉不同的量測角度位置之影像灰階值，經由計算後即可獲得散射光與表面粗糙度之間的關係。本論文使用6個標準金屬表面粗糙度試片進行實驗，其粗糙度為Ra = 0.05 μm、Ra = 0.1 μm、Ra = 0.2 μm、Ra = 0.4 μm、Ra = 0.8 μm、Ra = 1.6 μm。由不同偏振光源散射情況所獲得的光強分佈值並利用電腦程式進行分析，其結果顯示與金屬表面粗糙度Ra有良好的相關性，並將結果與金相顯微鏡量測的影像比較。此外，本文亦使用時域有限差分法來模擬金屬表面粗糙度的散射光場，藉以瞭解整個散射光場的情況。因此，本論文建構之非接觸式表面散射光量測儀，得以評估量測精密機械及光學元件的表面粗糙度。

關鍵字

偏振光 ； 表面粗糙度 ； CCD量測 ； 非接觸式

並列摘要

The thesis is mainly the application of techniques of polarized light scattering measurement to analyze the metal surface roughness to replace the traditional contact measurement, which can improve the speed and accuracy of the roughness measurement. The system we design for the thesis is non-contact measurement; therefore, it will not hurt the surface. Furthermore, it has advantages of high convenience, low prices of equipment, and so on. The measurement system uses a high collimated green laser irradiation on the metal surface. It measures the surface roughness scattering light distribution by the CCD camera. With calculations of the grayscale images measured by different angles, we will be able to learn about the relationship between scattered light and surface roughness. In this thesis, we conduct the experiment by using six standard specimens of metal surface roughness, the roughness (Ra) of which are respectively 0.05 μm, 0.1 μm, 0.2 μm, 0.4 μm, 0.8 μm, and 1.6 μm. We use a computer program to analyze the distribution of light intensity, which are calculated by different polarized light sources. The result shows great correlation with the metal surface roughness Ra, and then we compare the result with the images measured by metallurgical microscope. In addition, in order to understand the situation of the whole scattering light field, in this paper we also use FDTD method to simulate scattering light fields of metal surface roughness. As a result, the non-contact surveying instrument of surface scattering light that we construct for the thesis is able to measure and assess the roughness of surface of precision machinery and optical components.

並列關鍵字

polarized light ； surface roughness ； CCD measurement ； Non-contact

參考文獻

[21]劉承揚、劉子安、傅尉恩，應用於晶圓表面奈米微粒檢測的多方向偏振散射光量測儀，科儀新知的二十九卷第四期。

[2]Measured Light-Scattering Properties of Individual Aerosol Particles Compared to Mie Scattering Theory R. G. Pinnick, J. M. Rosen, and D. J. Hofmann.

[3]D. Rod White, Peter Saunders, Stuart J. Bonsey, John van de Ven, and Hamish Edgar, “Reflectometer for measuring the bidirectional reflectance of rough surfaces, ” APPLIED OPTICS, 1 June 1998, Vol. 37, No. 16.

[5]Pramod K. Rastogi, “Optical Measurement Techniques and Applications” , Artech House, Inc, 1997.

[6]Giuseppe Schirripa Spagnolo, and Dario Ambrosini, “Diffractive optical element based sensor for roughness measurement, ” Sensors and Actuators A100, 108-186, 2002.