Papers by Keyword: Brushing

Abstract: The paper deals with the issue of coating and surface finishing with edge preparation prior to the coating. Nanocomposite AlCrSiN hard coatings were deposited on WC-Co substrates with a negative substrate bias voltage in range of-80 to-120 V using cathodic arc evaporation system. The effect of variation in the bias voltage on the coating-substrate adhesion and nanohardness was investigated. The maximum nanohardness of coating was 37.7 ± 1.5 GPa with the good coating-substrate adhesion. Static Mercedes indentation test was performed on a Rockwell-type hardness tester. The indents were studied by scanning electron microscope to evaluate the coating-substrate adhesion. The H to E ratio that represents resistance to the plastic deformation was determined. The influence of surface roughness and time of used surface finishing methods on the coating-substrate adhesion was also investigated.

Abstract: Joining of steel and aluminum is a commonly applied manufacturing process to obtain lightweight components. Cold pressure welding by means of direct extrusion allows gaining high bond strengths between these two materials. The contacting surfaces are usually prepared by using scratch brushing to enhance the bond strength. Most studies have shown the benefit of the brushing whereas the resulting bond strength scatters. Variations in the parameters of the brush treatment are presumed to be a major cause for the variations in strength. Within the presented work, scratch brushing parameters are adjusted to further improve the resulting bond strength. Cracking of the surfaces at low strains is a beneficial effect to enhance the bond strength. Therefore, the crack formation of the surfaces brushed under different conditions is analyzed in tensile tests. Roughness, residual stresses and microstructural changes of the aluminum surfaces resulting from brushing processes are evaluated to enhance the understanding of the cracking mechanism. Concluding, the brushing parameters are adjusted to improve bond strengths up to the material strength of the used aluminum.

Abstract: After milling process burrs can form as a result of plastic deformation of the material. Wire brushing can be used as a fully automated method of deburring on machining centres. In order to provide the same effects after brush change it is important to precisely determine the tool diameter. The article presents the method of dynamic diameter determination of circular brushes, which is the diameter of the brush during rotation.

Abstract: The dependence of different brushing parameters during surface preparation on the resulting bonding strength for the roll-bonding of Mg-Mg composites was investigated. A parameter study with different brushing parameters was used to analyze the effect on surface roughness as pre-step for roll-bonding trials with different roughness ratio. Furthermore, the influence of different Mg alloys and of a roll-bonded Al-Mg-Al sandwich composite on the obtained bonding strength was investigated.

Abstract: The need for new cutting tool technologies is driven by the constantly increasing performance of machine tools and the rising market competition. Current research results show that an improved combination of the cutting edge macro- and microgeometry, together with an appropriate substrate and coating, leads to a significant enhancement of cutting tool performance. Furthermore, inappropriate cutting edge microgeometries cause, in addition to the higher production costs, a reduction of the tool life. Hence, it is essential to produce tailored cutting edge microgeometries with high precision and process reliability. This paper presents the influence of brushing process parameters on the size and the form of produced cutting edges of indexable inserts. This leads to a better understanding and higher quality of the cutting edge preparation process by means of abrasive brushes. Furthermore, the process reliability of 5-axes brushing is analyzed. An example of a tool life map presents the significantly enhanced tool performance through cutting edge preparation and its sensitivity towards varying the cutting edge microgeometry.