Influence of surface pre-treatments on the high-cycle fatigue behavior of Ti–6Al–4V – From anodizing to laser-assisted techniques

Taube, Alexander L.; Kurtović, Azra; Niendorf, Т.; Mertens, Tobias; Zinn, Carolin; Schaper, Mirko; Maier, Hans Jürgen

doi:10.1016/j.ijfatigue.2016.06.010

Cited by 12 publications

(3 citation statements)

References 41 publications

(104 reference statements)

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“…Eventually, the mechanical performance of the treated wires will be affected by the surface and the bulk microstructural characteristics, e.g., martensitic transformation and appearance of secondary phases, surface topography, residual stress, thickness of the affected layer and other factors in a highly combined fashion. The texturing of surfaces by laser treatment has been in focus of research for decades and, thus, ample examples can be found in the literature detailing complexity of these interrelations [ 33 , 34 , 35 , 36 ]. As the focus of present work was on the evaluation of the performance of the fibre-reinforced UHPC compound behaviour, an in-depth analysis of the mechanical behaviour of single fibres is clearly beyond the scope of present work.…”

Section: Discussionmentioning

confidence: 99%

Effect of Fibre Material and Fibre Roughness on the Pullout Behaviour of Metallic Micro Fibres Embedded in UHPC

et al. 2020

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The use of micro fibres in Ultra-High-Performance Concrete (UHPC) as reinforcement increases tensile strength and especially improves the post-cracking behaviour. Without using fibres, the dense structure of the concrete matrix results in a brittle failure upon loading. To counteract this behaviour by fibre reinforcement, an optimal bond between fibre and cementitious matrix is essential. For the composite properties not only the initial surfaces of the materials are important, but also the bonding characteristics at the interfacial transition zone (ITZ), which changes upon the joining of both materials. These changes are mainly induced by the bond of cementitious phases on the fibre. In the present work, three fibre types were used: steel fibres with brass coating, stainless-steel fibres as well as nickel-titanium shape memory alloys (SMA). SMA fibres have the ability of “remembering” an imprinted shape (referred to as shape memory effect), triggered by thermal activation or stress, principally providing for superior performance of the fibre-reinforced UHPC. However, previous studies have shown that NiTi-fibres have a much lower bond strength to the concrete matrix than steel fibres, eventually leading to a deterioration of the mechanical properties of the composite. Accordingly, the bond between both materials has to be improved. A possible strategy is to roughen the fibre surfaces to varying degrees by laser treatment. As a result, it can be shown that laser treated fibres are characterised by improved bonding behaviour. In order to determine the bond strength of straight, smooth fibres of different metal alloy compositions, the present study characterized multiple fibres in series with a Compact-Tension-Shear (CTS) device. For critical evaluation, results obtained by these tests are compared with the results of conventional testing procedures, i.e., bending tests employing concrete prisms with fibre reinforcements. The bond behaviour is compared with the results of the flexural strength of prisms (4 × 4 × 16 cm3) with fibre reinforcements.

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Section: Discussionmentioning

confidence: 99%

Effect of Fibre Material and Fibre Roughness on the Pullout Behaviour of Metallic Micro Fibres Embedded in UHPC

et al. 2020

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“…Thus, the abrupt decline of the integral width directly below the uppermost layers shown in Fig. 7(b) is thought to be induced by several factors, such as dislocation density, decreasing crystallite size, surface roughness, and an inhomogeneous distribution of micro stresses that is imposed by a higher number of defects [24].…”

Section: Residual Stress Analysismentioning

confidence: 99%

Microstructure and mechanical properties of laser surface treated 44MnSiVS6 microalloyed steel

Dewi

Fischer

Volpp

et al. 2020

Optics & Laser Technology

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“…The laser nano structuring is a fast, easy and cost-efficient procedure [3] which leads to an increased, open-porous surface structure that is characterized by various undercuts which offer the possibility of a strong interlocking connection between substrate an adhesive [4]. Several studies, especially on the structural bonding of titanium and aluminum, have revealed that a laser-induced nano structuring considerably improves the adhesion properties [5][6][7][8][9]. Preliminary investigations of the authors on hybrid structures out of steel or aluminum and carbon fiber reinforced polymers (CFRP) have shown that a laser pre-treatment of the metallic interface significantly increases the static and cyclic joint strength as well as the ageing resistance [10][11][12][13][14].…”

Section: Introductionmentioning

confidence: 99%

Polymer-Steel-Sandwich-Structures: Influence of Process Parameters on the Composite Strength

Lohr

Muth

Dreher

et al. 2019

KEM

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As the demand of the automotive and aerospace industries for lightweight and cost effective materials increases, it is necessary to combine different materials with respect to their lightweight and functional properties. The combination of polymer-steel-sandwich composites - which consist of a polymer core structure (transferring shear loads) and two metal face-layers (absorbing tensile and compression loads occurring at bending) - suite the need of minimizing weight per area under bending loads. The reduction of process steps can be achieved by connecting the face layers and core in-situ via an in-mold assembly process using variothermal processing. The injection mold hereby is heated near the melt temperature of the polymer with a variothermal water processing unit. Via contact heating inserted steel blanks are heated to the same temperature as the mold. This process enables the combination of the metal surface with the polymer core by infiltrating the micro or nano scale structure, which is generated by laser structuring or nano coating. Through the increased mold/blank surface temperature induced via variothermal heating the melt viscosity is lowered. This decreasing viscosity of the polymer melt hereby enables a higher degree of infiltration of the laser structured and nano coated blanks. This improved infiltration behavior is a key factor for the adhesion of the sandwich components and beneficial for the composites strength. Within this work two steel blanks are inserted into the mold to manufacture sandwich structures with steel face layers and a polymer (here: polylactidacid; PLA) core. As these sandwich composites are prone to bending failure, the 4-point-bending test is used to characterize the mechanical properties of this hybrid structure. The two surface treatments will also be compared concerning their mechanical interface properties with a shear edge test. The additional reduction on the polymer melt viscosity by means of gas inducing with chemical blowing agent is investigated on the laser structured surfaces only. To investigate the influence of the polymers melts viscosity on the bonding properties chemical blowing agent is added for some blanks.

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Influence of surface pre-treatments on the high-cycle fatigue behavior of Ti–6Al–4V – From anodizing to laser-assisted techniques

Cited by 12 publications

References 41 publications

Effect of Fibre Material and Fibre Roughness on the Pullout Behaviour of Metallic Micro Fibres Embedded in UHPC

Effect of Fibre Material and Fibre Roughness on the Pullout Behaviour of Metallic Micro Fibres Embedded in UHPC

Microstructure and mechanical properties of laser surface treated 44MnSiVS6 microalloyed steel

Polymer-Steel-Sandwich-Structures: Influence of Process Parameters on the Composite Strength

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