Surface roughness

Surface roughness is one of the main criteria for evaluating the strength of a part.The devastation faced by the item under the influence of variable loads, is explained in greater stress concentrations.The latter, in turn, occurs in the presence of irregularities.The lower the surface roughness, the lower the probability of formation of cracks due to metal fatigue.Processing parts (finishing, polishing, finishing, etc.) contributes to a significant increase in the fatigue strength.

The lower the surface roughness, the better the corrosion properties of the part.This is particularly important in cases where the processing of products not possible to apply the protective coating.Such detail, in particular, can be attributed engine cylinders.

low surface roughness is important in pairings that meet the thermal conductivity, tightness.This increases the ability to reflect electromagnetic, light and ultrasonic waves.In addition, the loss becomes smaller than the electromagnetic energy in the resonating systems waveguides becomes lower capacitance electrodes;also reduced gas emission and gas absorption in electronic devices is facilitated, thus cleaning parts of the adsorbed particles of dust, steam, gas.

Assessing the quality of the surface, the experts draw attention to the direction of the strokes, formed after machining or other processing.This indicator has an impact on the degree of strength of the press connection, certainty landings durability.The designer need to specify the direction of strokes in critical cases.This need may be, for example, arise in connection with the direction of the jet of gas or liquid on the parts or the direction of relative movement (sliding) of conjugates.Reduced wear to the minimum possible irregularities in the direction of the coincidence with the direction of the sliding parts.

surface waviness and roughness of small always meet the high precision that is connected not only with the working conditions of conjugate elements, but also with the need to obtain reliable results with measurements in production.Such processing components can be used to make products attractive appearance or for convenience when content items clean.

surface roughness measurement is made when necessary.Indicators are set according to the functionality of the product.If the quality requirements for parts are not made, then the control over the level of roughness is performed.It must be said that the claim does not include the evaluation of defects (presence of cavities, for example).Therefore, in controlling the surface roughness control of the influence of defects is eliminated.In some cases, the requirements can be set to the individual parts of one piece.

evaluation carried out by the roughness roughness (usually cross).To produce this sectional plane.To remove the roughness from the other irregularities with relatively large steps, it is performed in consideration of within a certain, fairly limited area.

Quantitative assessment and valuation is made on the six parameters.Thus, taking into account the three high-rise parameter for evaluating the surface roughness (Ra, Rz, Rmax), two stepper (S, Sm), as well as the index determines the relative length of the support profile (tp).