Effect of mechanical vibration on Ra, Rq, Rz, and Rt roughness parameters

The effect of mechanical vibration on the roughness parameters (Ra, Rq, Rz and Rt) obtained by an electromechanical surface roughness tester in two samples, a stainless steel with Ra equal to 0.369 mu m and a carbon steel with Ra of 5.342 mu m, is discussed in this article. The tests were performed by introducing vibration with different values of frequency and amplitude. The measurement uncertainty associated with all roughness parameters was estimated by applying the GUM method proposed in the JCGM 101. The analysis of variance (ANOVA) technique was applied, and it was observed that the variables frequency and acceleration plus interaction between them were statistically significant with a 95% confidence level for all parameters evaluated. In the stainless steel sample, frequency produced the greatest effects on the values of roughness parameters, except for Ra value, which was more influenced by the acceleration. It was also found that the effect of the interaction between frequency and acceleration produced significant effects on the values of Rq and Rz. In the carbon steel sample, the interaction between frequency and acceleration was the main generator of changes in the average values of all parameters evaluated. For Ra, Rq, and Rz, the frequency was also a statistically significant variable.