| 1. |
- Agic, Adnan, 1967-, et al.
(författare)
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Influence of radial depth of cut on entry conditions and dynamics in face milling application
- 2017
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Ingår i: Journal of Superhard Materials. - New York : Allerton Press. - 1063-4576 .- 1934-9408. ; 39:4, s. 259-270
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Tidskriftsartikel (refereegranskat)abstract
- The choice of milling cutter geometry and appropriate cutting data for certain milling application is of vital importance for successful machining results. Unfavorable selection of cutting conditions might give rise to high load impacts that cause severe cutting edge damage. Under some circumstances the radial depth of cut in combination with milling cutter geometry might give unfavorable entry conditions in terms of cutting forces and vibration amplitudes. This phenomenon is originated from the geometrical features that affect the rise time of the cutting edge engagement into workpiece at different radial depths of cut. As the radial depth of cut is often an important parameter, particularly when machining difficult-to-cut materials, it is important to explore the driving mechanism behind vibrations generation. In this study, acceleration of the workpiece is measured for different radial depths of cut and cutting edge geometries. The influence of the radial depth of cut on the dynamical behavior is evaluated in time and frequency domains. The results for different radial depths of cut and cutting geometries are quantified using the root mean square value of acceleration. The outcome of this research study can be used both for the better cutting data recommendations and improved tool design.
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| 2. |
- Bushlya, Volodymyr, et al.
(författare)
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Tool wear and tool life of PCBN, binderless cBN and wBN-cBN tools in continuous finish hard turning of cold work tool steel
- 2014
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Ingår i: Journal of Superhard Materials. - 1934-9408. ; 36:1, s. 49-60
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Tidskriftsartikel (refereegranskat)abstract
- The paper presents the results of comparative study of performance of cutting tools made of ceramic-bound, binderless cBN, and wBN-cBN tool materials. The tool performance was assessed by tool wear-resistance, values of cutting forces, parameters of machined surface quality, and the state of sub-surface layer generated in continuous turning of hardened cold work tool steel. The tests were carried out under conditions of high speed machining (v (c) = 120-180 m/min) both with and without a coolant. The best tool performance by the above-mentioned criteria is provided by a low-cBN material with ceramic binder.
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| 3. |
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| 4. |
- Hoier, Philipp, 1988, et al.
(författare)
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Characterization of tool wear when machining Alloy 718 with high-pressure cooling using conventional and surface-modified WC–Co tools
- 2017
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Ingår i: Journal of Superhard Materials. - : Allerton Press. - 1063-4576 .- 1934-9408. ; 39:3, s. 178-185
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Tidskriftsartikel (refereegranskat)abstract
- Coolant supplied by high pressure into the cutting zone has shown to lower thermal loads on the tool when machining difficult-to-cut materials as the Alloy 718. In this study, we investigate how the combination of high-pressure cooling and tool–surface modifications can lead to further improvements regarding tool life. The general approach is to enhance the coolant–tool interaction by increasing the contact area. Therefore, we machined cooling features into flank and rake faces of commercially available cemented tungsten carbide inserts. In this way, the surface area was increased by ~ 12%. After the cutting tests, the tools were analyzed by scanning electron microscopy combined with energy-dispersive X-ray spectroscopy. Compared with conventional tools, the tool modifications reduced the flank wear by 45% for the investigated cutting parameters. Furthermore, we were able to significantly increase the cutting speed and feed rate without failure of the tool. The investigated surface modifications have great potential to enhance the productivity of metal cutting processes.
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| 5. |
- Markocsan, Nicolaie, 1967-, et al.
(författare)
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MAX-phase coatings produced by thermal spraying
- 2017
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Ingår i: Journal of Superhard Materials. - : Allerton Press. - 1063-4576 .- 1934-9408. ; 39:5, s. 355-364
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents a comparative study on the Ti2AlC coatings produced by different thermal spray methods, as Ti2AlC is one of the most studied materials from the MAX-phase family. Microstructural analysis of coatings produced by High Velocity Air Fuel (HVAF), Cold Spray and High Velocity Oxygen Fuel (HVOF) has been carried out by means of the scanning electron microscopy equipped with an energy dispersive spectrometer (EDS). The volume fraction of porosity was determined using the ASTM standard E562. The phase characterization of the as-received powder and as-sprayed coatings was conducted using the X-ray diffraction with CrKα radiation. Impact of the spray parameters on the porosity and the mechanical properties of the coatings are discussed. The results show that the spraying temperature and velocity play a crucial role in coatings characteristics. © 2017, Allerton Press, Inc.
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| 6. |
- Turkevych, Dmytro, et al.
(författare)
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HP-HT sintering, microstructure, and properties of B6O- and TiC-containing composites based on cBN
- 2015
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Ingår i: Journal of Superhard Materials. - 1934-9408. ; 37:3, s. 143-154
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Tidskriftsartikel (refereegranskat)abstract
- The article presents a study of the potential for the use of B6O superhard boron suboxide as a binder in composite materials with a low cBN content. Superhard B6O is characterized by higher mechanical properties than TiC widely used in commercial materials today. Composites containing 60 vol % cBN and different binder compositions that included B6O and TiC have been sintered in a toroid-type high-pressure apparatus at a pressure of 7.7 GPa in a temperature range from 1500 to 2000 A degrees C. The microstructure, phase and elemental composition of the sintered materials have been examined via electron microscopy and X-ray diffraction analysis. Mechanical properties have been analyzed via indentation techniques. The performance of the cutting tools produced from the sintered composites has been evaluated in turning hardened cold work tool steel.
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