首页期刊导航|Key engineering materials
期刊信息/Journal information
Key engineering materials
Trans Tech Publications Ltd.
Key engineering materials

Trans Tech Publications Ltd.

半月刊

1013-9826

Key engineering materials/Journal Key engineering materials
正式出版
收录年代

    Cutting Edge Preparation by Means of Abrasive Brushing

    B. DenkenaL. de LeonE. BassettM. Rehe...
    P.1-7页
    查看更多>>摘要：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.
      原文链接:
    • NETL
    • NSTL
    • Trans Tech Publications Ltd

    Comparison of nitride and noble metal coatings for precision glass molding tools

    Fritz KlockeOlaf DambonKyriakos Georgiadis
    P.9-16页
    查看更多>>摘要：The complexity of optical components increases steadily in recent years, while their dimension decrease. This situation makes the production of state of the art optical components by grinding and polishing very difficult and expensive. However, the technology of precision glass molding can be used to replace these traditional manufacturing methods by a single step replicative process. To achieve economies of scale with precision glass molding, a long molding tool lifetime is necessary. This can only be realized by applying protective PVD coatings on the molding tool surfaces. Well known thin hard coatings like TiAIN or CrN, as well as noble metal coatings are possible candidates. However, practical testing of carious coating-glass combinations in precision glass molding machines is not feasible due to long process times that make such testing very expensive and time consuming. In this work, these coatings are compared with each other and in combination with various glass types by performing oxidation and contact angle tests. The results of these tests are compared to the results of practical tests, in order to determine to which extent such model tests can replace practical testing.
      原文链接:
    • NETL
    • NSTL
    • Trans Tech Publications Ltd

    Pre PVD-Coating Processes and Their Effect on Substrate Residual Stress in Carbide Cutting Tools

    Berend DenkenaBemd Breidenstein
    P.17-22页
    查看更多>>摘要：Cohesive damage of PVD-coated cemented carbide cutting tools is ascribed to the residual stress state of the substrate subsurface. The present paper shows the formation of the substrate residual stress in the process chain as well as the stability of the single process steps referred to the scattering of the residual stress values. Depth resolved residual stress measurements across coating and substrate subsurface show a layer in the substrate, where possibly tensile stress occurs, from where cohesive damage may be initialized during tool use. Results of experiments are presented, where the influence of parameter variations in pre coating processes on the residual stress state is investigated. The characteristics of compressive residual substrate stress during the final PVD-process is presented as well as a correlation between coating and substrate stress.
      原文链接:
    • NETL
    • NSTL
    • Trans Tech Publications Ltd

    Qualification of Coatings to Predict Wear Behavior of Micro Blasted Cutting Tools

    Fritz KlockeChristof GorgelsArne StuckenbergEmmanouil Bouzakis...
    P.23-29页
    查看更多>>摘要：In today's production engineering nearly every cutting tool is coated. In the field of coating technology and tool treatment blasting is a common way to increase tool life or hold it on a constant level for several reconditioning steps. The latest innovation referring blasting are micro blasted coatings. For this technology a parameter variation was examined and the consequential tool life was compared with common testing method for tool systems in order to qualify the coating treatment. The investigations were carried out using an aluminum and zirconium oxide as blasting abrasive and by varying the blasting parameters pressure and duration. Finally, the treatment led to an optimized tool wear behavior due to micro blasting of the coating and the wear behavior could be referenced against the testing methods.
      原文链接:
    • NETL
    • NSTL
    • Trans Tech Publications Ltd

    Diamond Cutting of FeN-Layers on steel substrates for Optical Mould Making

    E. BrinksmeierR. GlaebeJ. Osmer
    P.31-34页
    查看更多>>摘要：The mass production of glass or plastic components by replication techniques, like hot pressing or injection moulding, requires inserts made of temperature resistant and hard materials. Generating an optical surface finish in these materials is time consuming and difficult. By using thermo-chemically treated steels as mould materials diamond cutting processes generating high form accuracies and low surface roughness can be applied without significant tool wear.
      原文链接:
    • NETL
    • NSTL
    • Trans Tech Publications Ltd

    Coating development for gear cutting tools

    P.35-40页
    查看更多>>摘要：Pre-machining of gear wheels is often done by hobbing using a soft work-piece material. Today, almost all of the hobs are used with a hard coating to enhance their life-time considerably. This paper describes the results obtained with a tailored coating in a single tooth cutting test (fly cutting). We show that a nano-structured multi-layer coating based on AlCrN is able to protect a tool better than conventional single-layer coatings. The specific mechanical and structural properties of the coating are explained in detail.
      原文链接:
    • NETL
    • NSTL
    • Trans Tech Publications Ltd

    Nanostructured bionic PVD-coatings for forming tools

    Wolfgang TillmannEvelina VogliJan HerperMatthias Haase...
    P.41-48页
    查看更多>>摘要：It is very important to minimize wear and friction in forming processes in order to avoid adhesion between work piece and tool. For the realization of these requirements, the PVD-coating system CrAIN was deposited and tested on substrates made from high speed steel 1.3343 by means of a reactive sputter process. The coatings were deposited as single- and multilayers with a metallic Cr-interlayer.Prior to realizing the appropriate coating design, the substrates were pre-structured. For this purpose natural surfaces were used as a pattern and tested in this research work. The skin of an insect serves as a model and its fine structures were reproduced on the substrate surface by milling. The generated specimens were analyzed with a scanning electron microscope, nanoindenter and ball-on-disc tester to compare the performance of the coating systems.
      原文链接:
    • NETL
    • NSTL
    • Trans Tech Publications Ltd

    Chip Length Effect on the Wear of Coated Cemented Carbide Inserts in Milling

    K.-D. BouzakisS. GerardisG. KatirtzoglouS. Makrimallakis...
    P.49-56页
    查看更多>>摘要：The effect of the developed chip length on the coated tool's cutting performance was investigated. Milling experiments at various cutting speeds and chip lengths were performed, which resulted to different tool wear developments. To explain these results, a FEM simulation of the cutting process was conducted and the related chip geometries were predicted and compared to the corresponding experimental ones. Based on these results, the Coulomb friction coefficient between chip and tool rake was appropriately adjusted to achieve a sufficient correlation between experimental and computational data. By additional FEM calculations, the mechanical and thermal loads of the cutting edge were estimated and insight was provided concerning the effect of chip length on coated tool stresses and film fatigue fracture. The obtained results revealed that the chip length reduction improves the cutting performance of coated tools and a significant increase of the removed material volume and material removal rate as well can be achieved.
      原文链接:
    • NETL
    • NSTL
    • Trans Tech Publications Ltd

    Impact Behaviour of Ptlr-based Coatings with Different Interlayers for Glass Lens Moulding

    Kirsten BobzinFritz KlockeNazlim BagcivanMara Ewering...
    P.57-64页
    查看更多>>摘要：Over the last decades demands for optical systems and complex optical products made of glass increased steadily. Precision glass moulding has a great potential for the bulk production of complex lenses with high precision and low costs. To prevent sticking or reactions between hot glass and moulding, and to reduce abrasive wear of the die a protective coating is deposited on the tool. In this research two coating systems suitable for this application are compared by analysing their behaviour under an impact load. The PVD (Physical Vapor Deposition) coating Ptlr with two different bond coatings Ni or Cr is analysed. During impact test number of impacts and loads are varied. Compared to industrially used coating system Ptlr with a Ni interlayer the adhesion can be improved by using a Cr interlayer. The Ptlr-based coating with Cr as bond coating shows an excellent endurance even at very high loads causing Hertzian stresses in the range of 10 - 14 GPa. An impact load of 600 N which corresponds to a contact pressure of app. 13.2 GPa generates almost no damage after 200,000 impacts.
      原文链接:
    • NETL
    • NSTL
    • Trans Tech Publications Ltd

    Diamond Machinable Sol-Gel Silica Based Hybrid Coatings for High Precision Optical Molds

    Andreas MehnerJuan DongTimo HojaTorsten Prenzel...
    P.65-72页
    查看更多>>摘要：The demand for high precision optical elements as micro lens arrays for displays increases continually. Economic mass production of such optical elements is done by replication with high precision optical molds. A new approach for manufacturing such molds was realized by diamond machinable and wear resistant sol-gel coatings. Crack free silica based hybrid coatings from base catalyzed sols from tetraethylorthosilicate (TEOS: Si(OC_2H_5)_4) and methyltriethoxysilane (MTES: Si(CH_3)(OC_2H_5)_3) precursors were deposited onto pre-machined steel molds by spin coating process followed by a heat treatment at temperatures up to 800℃. Crack-free multilayer coatings with a total thickness of up to 18 μm were achieved. Micro-machining of these coatings was accomplished by high precision fly cutting with diamond tools. Molds with micro-structured coatings were successfully tested for injection molding of PMMA optical components. The wear resistance of the coatings was successfully tested by injection molding of 1000 PMMA lenses. Hardness and elastic modulus of the coatings were measured by nano indentation. The chemical composition was measured by X-ray photo electron spectroscopy (XPS) as a function of the sol-gel processing parameters.
      原文链接:
    • NETL
    • NSTL
    • Trans Tech Publications Ltd