High Performance Grinding and Advanced Cutting Tools

The studies described in this paper focus on the wear behavior of duplex grade abrasive segments grinding AISI 1020 and A36 steels on a vertical spindle surface grinding machine (VSSG). The study focuses on the behavior of the abrasive segment and how it contributes to significant changes in the grinding ratio and the type of wear that is occurring under grinding conditions where short chips are generated (roughness ratio, λ > 1) and accumulate in the graded structure of the abrasive segment. The paper discusses the kinematics of the VSSG process, the mechanisms of wear in abrasive and bonded grains, the VSSG experiments performed, and the results generated in terms of segment wear and the resulting roughness of the ground surfaces. The analysis of the results concludes by stating that duplex graded segments are useful in controlling the phenomena of "chip crowding," although this may lead to "parasitic wear" to take place that may negatively affect segment performance in VSSG operations. In this respect, the paper addresses the type of abrasive grain to be used during VSSG operations. The studies described in this paper may be useful to manufacturing engineers who use VSSG operations and are responsible for their development.

Section: Discussion Of Experimental Resultsmentioning

confidence: 99%

Vertical spindle surface grinding of AISI 1020 and A36 steels using duplex grade vitrified abrasive segments

Jackson

Whitfield

Burgess

2016

“…For this study, p varies from 50 to 80. Given that most grain cutting edges have −60°or more negative rake angle [28], q is determined by measuring the rake angle of every GE (see Fig. 9(d)).…”

Section: Determination Of P and Qmentioning

confidence: 99%

Modeling and simulation of grinding wheel by discrete element method and experimental validation

Zhu

et al. 2015

A simulated grinding wheel (GW), a numerical representative that describes the geometric and physical properties of realistic GWs, is the prerequisite and foundation of grinding research. However, most proposed numerical GWs treated realistic GWs as continuums without internal structure (e.g., binder and pores) and analyzed realistic GWs' behaviors based on continuum-based material theories. To fill this gap, this study attempts to introduce a discontinuum-based method, discrete element method (DEM), into GW modeling and simulation. DEM GW simulation begins with two grindingcustomized modifications to classic DEM theory. Then, with the aid of experimental measurement and statistical analysis, a DEM GW is modeled. Experimental validations are conducted thereafter. Results show acceptable agreements between DEM and realistic GWs in terms of topography, microscopic structure, fracture behavior in compressive test, and performance in grinding process. The proposed DEM GW's ability in describing a discontinuous structure of realistic GWs covers the shortage of existing numerical GWs and might have other promising applications (e.g., GW formula optimization in production, GW preparation technology and parameter optimization, and GW wear and life prediction).Keywords Discrete element method . Grinding wheel . Modeling and simulationAbbreviation Scalar (in alphabetical order) a bHalf the length of octahedron minor axis (see Fig. 8a) a tHalf the length of spheriod minor axis (see Fig. 8aHalf the length of octahedron major axis (see Fig. 8a) b tHalf the length of spheriod major axis (see Fig. 8a)

“…When machining abrasion-resistant materials such as composites of metal-ceramic matrix with non-ferrous metals (in particular aluminum and titanium) and its alloys reinforced with hard particles and composites of plastics reinforced with glass fibers, cemented carbide tools are being replaced by considerably more expensive, but more abrasion-resistant polycrystalline diamond (PCD) tools [1][2][3]. The wear resistance of cemented carbides can be significantly increased, while retaining their high fracture toughness, by replacing part of the carbide phase with cubic boron nitride grains as a dispersive phase.…”

Section: Introductionmentioning

confidence: 99%

The influence of the diamond wheel grinding process on the selected properties of boron nitride dispersion in cemented carbide (BNDCC) composites

Staniewicz-Brudnik

Karolus

Bączek

et al. 2017

The paper presents the results of research into the influence of the process of grinding boron nitride dispersed cemented carbide (BNDCC) composite using diamond wheel with vitrified bond on the selected properties of this composite. Cutting tools of BNDCC composite were manufactured using several machining operations. At first stage, they were EDM (electrical discharge machining) wire cut from tablets and later on ground with diamond wheels (which removed the "white layer" produced by EDM cutting). Rake and flank faces of prepared cutting tools were examined by microscopic, topographic, and surface analytical techniques before and after grinding. The paper presents comparative results of BNDCC tools and tools made of H10S cemented carbide. Values of the grinding efficiency parameters, Q w , average material removal rate of grinding, Q′ w , average material removal rate per unit active grinding wheel for the two materials, were similar, indicating an insignificant effect of introduction of the harder BN phase into WCCo on these parameters. R a , surface roughness of flank face, was 0.040 μm for BNDCC composite and 0.51 μm for H10S after grinding, compared to 1.14 and 1.30 μm, respectively, before grinding. WC residual stress measurements in the flank faces of BNDCC tools were inconclusive; in the flank faces, the stresses were compressive, decreasing, e.g., from − 230 to − 1670 MPa after grinding. For the H10S tools, there was no comparable effect. The results also indicate that the vitrified bonded diamond abrasive wheel used is effective in grinding WCCo and BNDCC cutting tools.