Thermal Sources of Errors in Surface Texture Imaging

Karol Grochalski,Michał Wieczorowski,Jihad H’Roura,Paweł Pawlus

doi:10.3390/ma13102337

Abstract

This paper presents the influence of thermal phenomena on areal measurements of surface topography using contact profilometers. The research concerned measurements under controlled and variable environmental conditions. The influence of internal heat sources from profilometer drives and their electronic components was analyzed. For this purpose, a thermal chamber was designed and built. Its task was to maintain and control environmental conditions and, at the same time, separate the profilometer from external disturbances. Heat sources and temperature values for elements and systems were determined. It further enabled for the calculation of the displacements in axes as a function of temperature. The largest displacement in the probe due to internal heat sources for the considered cases occurred in the X-axis direction. Its value reached 16.2 μm. However, the displacement in the probe in the Z-axis direction had the greatest impact on the measured surface topography. These displacements for a thermally unstable profilometer reached 7.9 μm in Z, causing results even 90% greater than in the case of a device without such problems. The time after which a proper topography measurement can be started was also determined basing on obtained data. This time for tested profilometers was between 6 and 12 h. It was found that performing thermal stabilization of the profilometer significantly reduced surface irregularity errors. The stabilization time should be determined individually for a specific type of device.

Highlights

IntroductionThe improvement in the quality of manufacturing processes of machinery and equipment parts is directly related to the development (advancement) of methods to control manufactured products
The improvement in the quality of manufacturing processes of machinery and equipment parts is directly related to the development of methods to control manufactured products.This is associated with the simultaneous development of quality control departments and the use of more and more advanced measuring devices
The topic is an important issue as it is generally believed that there is no thermal influence on performance of a profilometer, which is commonly used for tactile surface topography measurements

Summary

Introduction

The improvement in the quality of manufacturing processes of machinery and equipment parts is directly related to the development (advancement) of methods to control manufactured products. An important issue in the assessment of the structure condition is broadly understood surface irregularities They are one of the basic features determining the quality of manufactured parts that affect their performance, durability, and exchangeability in mechanical engineering [2]. There are sophisticated methods of filtration, enabling the separation of particular components, e.g., the component of a shape deviation or waviness, which, as a result, enables the roughness analysis. They often reach even more and more multiscale analysis for different purposes [5,6]. The data set covering many aspects of the measurement, e.g., environmental factors, device status, and signal processing algorithms, allows the most advantageous analysis of the obtained values and their possible correct interpretation

Problem Statement

Materials, Methods, and Results

Static Measurement

Dynamic Measurement

Conclusions