Investigation on the Influence of Manufacturing Parameters on the Fatigue Strength of Components

2013 ◽  
Vol 554-557 ◽  
pp. 280-286 ◽  
Author(s):  
Andrea Reiss ◽  
Ulf Engel ◽  
Marion Merklein
Keyword(s):  
Fatigue Strength ◽  
Surface Quality ◽  
Fatigue Behavior ◽  
High Surface ◽  
Research Work ◽  
Cold Forging ◽  
Hardness Distribution ◽  
Forming Process ◽  
High Surface Quality ◽  
Manufacturing Parameters

With cold forging processes it is possible to produce parts characterized by high strength, high dimensional accuracy and high surface quality. In order to optimize the forming process and to be able to use the advantages of cold forging specifically and combined, it is necessary to find correlations between the manufacturing parameters, the strength and the properties, like hardness distribution and surface quality, of the component. The research work covered in this paper focuses on the influence of the components properties influenced by its manufacturing history on their fatigue strength. The used component is a flange hub, produced by a four-stage cold forging process. To obtain different component properties the production process of the hub was varied for example by changing the heat treatment or by producing the parts by turning process. First of all, the components’ properties, for example hardness distribution, remaining residual stresses, orientation of fibers and surface quality, were determined. Moreover, a special experimental setup for the fatigue tests has been designed. The components’ fatigue behavior was determined using a high frequency pulsator and evaluated in terms of finite life fatigue strength and fatigue endurance limit. These examinations were used to produce Woehler curves for the differently manufactured components with a certain statistical data analysis method.

Influence of Manufacturing Process on the Fatigue Strength of Gears

2014 ◽  
Vol 1018 ◽  
pp. 269-276
Author(s):  
Andrea Reiß ◽  
Ulf Engel
Keyword(s):  
Fatigue Strength ◽  
Surface Quality ◽  
Fatigue Behavior ◽  
High Surface ◽  
Research Work ◽  
Dimensional Accuracy ◽  
Cold Forging ◽  
Hardness Distribution ◽  
Forming Process ◽  
High Surface Quality

With cold forging processes it is possible to produce parts characterized by high strength, high dimensional accuracy and high surface quality. In order to optimize the forming process and to be able to use the advantages of cold forging specifically and combined, it is necessary to find correlations between manufacturing parameters on the one side, strength and other properties like hardness distribution and surface quality of the component on the other side. The research work covered in this paper focuses on the correlation of the components properties influenced by its manufacturing history and their fatigue strength. The used component is a gear produced by a lateral cold forging process. For the investigations an experimental setup has been designed. The aim for the design of the setup is to reproduce the real contact condition for the contact of two gears. To obtain different component properties the production process of the gear was varied by producing the parts by a milling operation. First of all, the components’ properties, for example hardness distribution, remaining residual stresses, orientation of fibers and surface quality, were determined. The components’ fatigue behavior was determined using a high frequency pulsator and evaluated in terms of finite life fatigue strength and fatigue endurance limit. These examinations were used to produce Woehler curves for the differently manufactured components with a certain statistical data analysis method.

scholarly journals Experimental investigation of the machining characteristics in diamond wire sawing of unidirectional CFRP

2021 ◽  
Author(s):  
Lukas Seeholzer ◽  
Stefan Süssmaier ◽  
Fabian Kneubühler ◽  
Konrad Wegener
Keyword(s):  
Surface Quality ◽  
Influencing Factors ◽  
Material Properties ◽  
High Surface ◽  
Workpiece Surface ◽  
High Surface Quality ◽  
High Productivity ◽  
Surface Temperatures ◽  
Process Forces ◽  
The Wire

AbstractEspecially for slicing hard and brittle materials, wire sawing with electroplated diamond wires is widely used since it combines a high surface quality with a minimum kerf loss. Furthermore, it allows a high productivity by machining multiple workpieces simultaneously. During the machining operation, the wire/workpiece interaction and thus the material removal conditions with the resulting workpiece quality are determined by the material properties and the process and tool parameters. However, applied to machining of carbon fibre reinforced polymers (CFRP), the process complexity potentially increases due to the anisotropic material properties, the elastic spring back potential of the material, and the distinct mechanical wear due to the highly abrasive carbon fibres. Therefore, this experimental study analyses different combinations of influencing factors with respect to process forces, workpiece surface temperatures at the wire entrance, and the surface quality in wire sawing unidirectional CFRP material. As main influencing factors, the cutting and feed speeds, the density of diamond grains on the wire, the workpiece thickness, and the fibre orientation of the CFRP material are analysed and discussed. For the tested parameter settings, it is found that while the influence of the grain density is negligible, workpiece thickness, cutting and feed speeds affect the process substantially. In addition, higher process forces and workpiece surface temperatures do not necessarily deteriorate the surface quality.

scholarly journals Investigation on the Surface Quality Obtained during Trochoidal Milling of 6082 Aluminum Alloy

Machines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 75
Author(s):  
Nikolaos E. Karkalos ◽  
Panagiotis Karmiris-Obratański ◽  
Szymon Kurpiel ◽  
Krzysztof Zagórski ◽  
Angelos P. Markopoulos
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Process Parameters ◽  
Manufacturing Industry ◽  
High Surface ◽  
Cutting Tools ◽  
Cutting Speed ◽  
Depth Of Cut ◽  
High Surface Quality ◽  
Trochoidal Milling

Surface quality has always been an important goal in the manufacturing industry, as it is not only related to the achievement of appropriate geometrical tolerances but also plays an important role in the tribological behavior of the surface as well as its resistance to fatigue and corrosion. Usually, in order to achieve sufficiently high surface quality, process parameters, such as cutting speed and feed, are regulated or special types of cutting tools are used. In the present work, an alternative strategy for slot milling is adopted, namely, trochoidal milling, which employs a more complex trajectory for the cutting tool. Two series of experiments were initially conducted with traditional and trochoidal milling under various feed and cutting speed values in order to evaluate the capabilities of trochoidal milling. The findings showed a clear difference between the two milling strategies, and it was shown that the trochoidal milling strategy is able to provide superior surface quality when the appropriate process parameters are also chosen. Finally, the effect of the depth of cut, coolant and trochoidal stepover on surface roughness during trochoidal milling was also investigated, and it was found that lower depths of cut, the use of coolant and low values of trochoidal stepover can lead to a considerable decrease in surface roughness.

scholarly journals Fatigue Behavior of Non-Optimized Laser-Cut Medical Grade Ti-6Al-4V-ELI Sheets and the Effects of Mechanical Post-Processing

Metals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 843 ◽  
Author(s):  
André Reck ◽  
André Till Zeuner ◽  
Martina Zimmermann
Keyword(s):  
Surface Roughness ◽  
Fatigue Strength ◽  
Surface Quality ◽  
Laser Cutting ◽  
Fatigue Behavior ◽  
Fatigue Cracks ◽  
Surface Condition ◽  
Mechanical Polishing ◽  
Fatigue Properties ◽  
Post Processing

The study presented investigates the fatigue strength of the (α+β) Ti-6Al-4V-ELI titanium alloy processed by laser cutting with and without mechanical post-processing. The surface quality and possible notch effects as a consequence of non-optimized intermediate cutting parameters are characterized and evaluated. The microstructural changes in the heat-affected zone (HAZ) are documented in detail and compared to samples with a mechanically post-processed (barrel grinding, mechanical polishing) surface condition. The obtained results show a significant increase (≈50%) in fatigue strength due to mechanical post-processing correlating with decreased surface roughness and minimized notch effects when compared to the surface quality of the non-optimized laser cutting. The martensitic α’-phase is detected in the HAZ with the formation of distinctive zones compared to the initial equiaxial α+β microstructure. The HAZ could be removed up to 50% by means of barrel grinding and up to 100% through mechanical polishing. A fracture analysis revealed that the fatigue cracks always initiate on the laser-cut edges in the as-cut surface condition, which could be assigned to an irregular macro and micro-notch relief. However, the typical characteristics of the non-optimized laser cutting process (melting drops and significant higher surface roughness) lead to early fatigue failure. The fatigue cracks solely started from the micro-notches of the surface relief and not from the dross. As a consequence, the fatigue properties are dominated by these notches, which lead to significant scatter, as well as decreased fatigue strength compared to the surface conditions with mechanical finishing and better surface quality. With optimized laser-cutting conditions, HAZ will be minimized, and surface roughness strongly decreased, which will lead to significantly improved fatigue strength.

Variothermal Foam Injection Molding - Dimensional Stability with High Surface Quality

2017 ◽  
Vol 36 (3) ◽  
pp. 151-166 ◽  
Author(s):  
Christian Hopmann ◽  
Nicolai Lammert ◽  
Yuxiao Zhang
Keyword(s):  
Surface Quality ◽  
Surface Defects ◽  
Control Strategies ◽  
High Surface ◽  
Skin Layer ◽  
High Surface Quality ◽  
Major Disadvantage ◽  
Scope Of Application ◽  
Specific Material ◽  
Foam Injection Molding

Thermoplastic foam injection moulding offers various advantages for both processing and product design. Despite its many benefits, the moderate surface quality still constitutes a major disadvantage of this process. The mould temperature can be controlled dynamically to improve the surface quality. Different dynamic temperature control strategies are employed and analysed regarding their effectiveness and scope of application. Mould temperatures above the specific material transition temperatures allow the surface defects to be cured and enable the production of foamed thermoplastic parts with surface qualities comparable to those of the compact reference samples. The high mould temperatures during the injection phase alter the foam structure and the skin layer thicknesses, which impacts the mechanical properties.

scholarly journals Electropolishing Parametric Optimization of Surface Quality for the Fabrication of a Titanium Microchannel Using the Taguchi Method

Machines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 325
Author(s):  
Muslim Mahardika ◽  
Martin Andre Setyawan ◽  
Tutik Sriani ◽  
Norihisa Miki ◽  
Gunawan Setia Prihandana
Keyword(s):  
Taguchi Method ◽  
Surface Quality ◽  
Process Parameters ◽  
Applied Voltage ◽  
High Surface ◽  
Machining Process ◽  
Machining Parameters ◽  
Pareto Analysis ◽  
High Surface Quality

Titanium is widely used in biomedical components. As a promising advanced manufacturing process, electropolishing (EP) has advantages in polishing the machined surfaces of material that is hard and difficult to cut. This paper presents the fabrication of a titanium microchannel using the EP process. The Taguchi method was adopted to determine the optimal process parameters by which to obtain high surface quality using an L9 orthogonal array. The Pareto analysis of variance was utilized to analyze the three machining process parameters: applied voltage, concentration of ethanol in an electrolyte solution, and machining gap. In vitro experiments were conducted to investigate the fouling effect of blood on the microchannel. The result shows that an applied voltage of 20 V, an ethanol concentration of 20 vol.%, and a machining gap of 10 mm are the optimum machining parameters by which to enhance the surface quality of a titanium microchannel. Under the optimized machining parameters, the surface quality improved from 1.46 to 0.22 μm. Moreover, the adhesion of blood on the surface during the fouling experiment was significantly decreased, thus confirming the effectiveness of the proposed method.

Research of Grinding Material Tools by Modern Grinding Wheels

2013 ◽  
Vol 581 ◽  
pp. 211-216 ◽  
Author(s):  
Jiří Čop ◽  
Imrich Lukovics
Keyword(s):  
Boron Nitride ◽  
Surface Quality ◽  
High Surface ◽  
Cubic Boron Nitride ◽  
High Accuracy ◽  
Grinding Wheels ◽  
Cutting Depth ◽  
High Surface Quality ◽  
Materials Used

This research paper focuses on grinding of materials used for tools (100Cr6 (CSN 4 14109), X210Cr12 ( CSN 4 19436) and epoxy resin) using grinding wheels from cubic boron nitride and diamond. The disadvantage of grinding of difficult-to-machine materials is higher wear of grinding wheels. The modern grinding wheels are able to achieve high accuracy of dimensions and high surface quality with a smaller wear of grinding wheels then grinding wheels from conventional materials. Correctly selected technological conditions are one of the most important matters to achieve the required surface quality. The main aim of this research is to determine the influence of technological conditions to quality of surface after planar grinding. The research determines the influence of the grain type of grinding wheels, feed rate and cutting depth on the quality of functional surfaces.

Precision glass molding of diffractive optical elements with high surface quality

2020 ◽  
Vol 45 (23) ◽  
pp. 6438
Author(s):  
Yingying Zhang ◽  
Rongguang Liang ◽  
Oliver Joshua Spires ◽  
Shaohui Yin ◽  
Allen Yi ◽  
...  
Keyword(s):  
Surface Quality ◽  
High Surface ◽  
Diffractive Optical Elements ◽  
Optical Elements ◽  
Glass Molding ◽  
High Surface Quality ◽  
Precision Glass Molding
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