Herstellungsprozess und Wälzfestigkeit von hybriden Hochleistungsbauteilen/Manufacturing of Hybrid High-Performance Components under Rolling Contact Fatigue

Konstruktion ◽  
2018 ◽  
Vol 70 (09) ◽  
pp. 84-89
Author(s):  
Maximilian Mildebrath ◽  
Hans Jürgen Maier ◽  
Thomas Hassel ◽  
Timm Coors ◽  
Florian Pape ◽  
...  
Keyword(s):  
Material Properties ◽  
High Performance ◽  
Materials Science ◽  
Steel Substrate ◽  
Construction Material ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Industrial Applications ◽  
Rolling Contact ◽  
Tailored Forming

Inhalt: Moderne Massivbauteile werden herkömmlich aus Monomaterialien gefertigt. Viele Bauteile besitzen dabei Funktions- und Strukturbereiche, welche durch unterschiedliche Beanspruchungsprofile sehr unterschiedliche Anforderungen an den Konstruktionswerkstoff stellen. Somit ermöglicht das eingesetzte Material oft nur einen Kompromiss hinsichtlich der geforderten Materialeigenschaften und der Leistungsfähigkeit des Bauteils. Im Sonderforschungsbereich 1153 „Tailored Forming“ an der Leibniz Universität Hannover (LUH) werden neue Prozessketten zur Realisierung hoch belastbarer hybrider Massivbauteile entwickelt. In Zusammenarbeit des Instituts für Werkstoffkunde (IW) und des Instituts für Maschinenkonstruktion und Tribologie (IMKT) wurden hybride Lagerscheiben zum Einsatz als Axial-Zylinderrollenlagern entwickelt. Diese wurden mittels Plasma-Pulver-Auftragschweißen (PPA) aus Vergütungsstahl hergestellt (Bild 1) und anschließend bezüglich Ihrer Wälzfestigkeit untersucht. Diese Untersuchungen dienen als Grundlage zur Evaluierung von Leistungsfähigkeit und Qualität des Beschichtungsprozesses sowie der Materialeigenschaften. Mit ersten hybrid hergestellten Rohlingen werden Maschinenelemente gefertigt, um die Eignung des Prozesses für industrielle Anwendungen zu bewerten.   Abstract: Modern solid components are conventionally manufactured from monomaterials. Many components are equipped with functional and structural areas, which have to fulfil various demands regarding the construction material due to different stress profiles. Thus, the applied material offers a trade-off concerning the required material properties and the performance of the component. The Collaborative Research Center 1153 „Tailored Forming“ at Leibniz Universität Hannover (LUH) is developing new process chains for the realization of highly resilient hybrid solid components. In cooperation with the Institute of Materials Science (IW) and the Institute of Machine Design and Tribology (IMKT), multi-material bearing discs were developed for use as cylindrical roller thrust bearings. These were produced by plasma powder deposition welding (PPA) from heat treatable steel (Figure 1) on a steel substrate and then tested under rolling contact loads. These investigations serve as a basis for evaluating the performance and quality of the coating process as well as the material properties. In this publication, the above concept was proven for first hybrid produced workpieces in order to assess the suitability of the process for industrial applications.

A Rolling Contact Fatigue Reliability Evaluation Method and its Application to a Slewing Bearing

2012 ◽  
Vol 134 (1) ◽  
Author(s):  
Gao Xue Hai ◽  
Huang Xiao Diao ◽  
Hong Rong Jing ◽  
Wang Hua ◽  
Chen Jie
Keyword(s):  
Material Properties ◽  
Evaluation Method ◽  
Rolling Contact Fatigue ◽  
Oscillation Amplitude ◽  
Contact Fatigue ◽  
Operating Conditions ◽  
Rolling Contact ◽  
Fatigue Reliability ◽  
Stochastic Behavior ◽  
Slewing Bearing

Rolling contact fatigue (RCF) corresponds to the formation of the first spall, which is a stochastic behavior; therefore, the RCF life should be reliably calculated. A method for evaluating RCF reliability was developed based on the Lundberg-Palmgren theory and ISO 281. The method took into consideration the contact load, the geometric parameters of contact pairs, the oscillation amplitude, the RCF reliability and the material properties. Because the method was derived from a widely accepted theory and empirical standards, it can be used for engineering applications. Finally, the RCF reliability of a slewing bearing under complex operating conditions was determined using the developed method.

18CrNiMo7-6 with TRIP-Effect for Increasing the Damage Tolerance of Gear Components — Part I: Alloy Design

2014 ◽  
Vol 783-786 ◽  
pp. 633-638
Author(s):  
Margarita D. Bambach ◽  
Andreas Stieben ◽  
Wolfgang Bleck
Keyword(s):  
High Performance ◽  
Damage Tolerance ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
High Strength ◽  
Residual Austenite ◽  
Rolling Contact ◽  
Optimum Process ◽  
Trip Effect ◽  
Stress Concentrations

High performance components such as gear wheels shall be resistant to rolling-contactfatigue. This type of failure is usually caused by effects occurring on a microscopic scale, such ascrack initiation at non-metallic inclusions. Much effort has been invested so far in improving thesteel cleanliness. However, these high performance components often do not reach the desiredservice life. Preliminary failure within the guarantee terms still occurs which leads to high warrantycosts. Alternative to improving steel cleanliness, the damage tolerance of high performancecomponents could be increased by inducing the TRIP-effect around the crack tip. Due to high localstrain hardening, martensite transformation occurs. The high compressive stresses related to it coulddelay or stop crack propagation by reducing stress concentrations via plastic deformation. As aresult, rolling-contact fatigue resistance of carburized steels may be increased and preliminaryfailure may be avoided. Part I of this study focuses on modifying the chemical composition ofconventional 18CrNiMo7-6 steel with Al to develop a high-strength, yet ductile matrix with a highwork hardening potential. Dilatometric tests on laboratory melts analyze the possibility of adjustinga microstructure able to produce a TRIP-effect. Both isothermal annealing and Quenching andPartitioning (Q&P) are used to stabilize residual austenite and optimum process routes areidentified.

Influence of Initial Residual Stress on Material Properties of Bearing Steel During Rolling Contact Fatigue

2014 ◽  
Vol 57 (3) ◽  
pp. 533-545 ◽  
Author(s):  
Bryan Allison ◽  
Ghatu Subhash ◽  
Nagaraj Arakere ◽  
David A. Haluck ◽  
Herb Chin
Keyword(s):  
Residual Stress ◽  
Material Properties ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Bearing Steel ◽  
Rolling Contact ◽  
Initial Residual Stress

A 3D Finite Element Study of Fatigue Life Dispersion in Rolling Line Contacts

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Nick Weinzapfel ◽  
Farshid Sadeghi ◽  
Vasilios Bakolas ◽  
Alexander Liebel
Keyword(s):  
Finite Element ◽  
Shear Stress ◽  
Material Properties ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Critical Shear Stress ◽  
Rolling Contact ◽  
Shear Stresses ◽  
Rolling Element Bearings ◽  
Rolling Element

Rolling contact fatigue of rolling element bearings is a statistical phenomenon that is strongly affected by the heterogeneous nature of the material microstructure. Heterogeneity in the microstructure is accompanied by randomly distributed weak points in the material that lead to scatter in the fatigue lives of an otherwise identical lot of rolling element bearings. Many life models for rolling contact fatigue are empirical and rely upon correlation with fatigue test data to characterize the dispersion of fatigue lives. Recently developed computational models of rolling contact fatigue bypass this requirement by explicitly considering the microstructure as a source of the variability. This work utilizes a similar approach but extends the analysis into a 3D framework. The bearing steel microstructure is modeled as randomly generated Voronoi tessellations wherein each cell represents a material grain and the boundaries between them constitute the weak planes in the material. Fatigue cracks initiate on the weak planes where oscillating shear stresses are the strongest. Finite element analysis is performed to determine the magnitude of the critical shear stress range and the depth where it occurs. These quantities exhibit random variation due to the microstructure topology which in turn results in scatter in the predicted fatigue lives. The model is used to assess the influence of (1) topological randomness in the microstructure, (2) heterogeneity in the distribution of material properties, and (3) the presence of inherent material flaws on relative fatigue lives. Neither topological randomness nor heterogeneous material properties alone account for the dispersion seen in actual bearing fatigue tests. However, a combination of both or the consideration of material flaws brings the model’s predictions within empirically observed bounds. Examination of the critical shear stress ranges with respect to the grain boundaries where they occur reveals the orientation of weak planes most prone to failure in a three-dimensional sense that was not possible with previous models.

Observation of Crack Propagation in PEEK Polymer Bearings under Water-Lubricated Conditions

2012 ◽  
Vol 566 ◽  
pp. 109-114 ◽  
Author(s):  
Hitonobu Koike ◽  
Katsuyuki Kida ◽  
Takashi Honda ◽  
Koshiro Mizobe ◽  
Shunsuke Oyama ◽  
...  
Keyword(s):  
Crack Propagation ◽  
High Performance ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Practical Applications ◽  
Performance Engineering ◽  
Poly Ether Ether Ketone ◽  
Laser Confocal Microscope ◽  
Circular Cracks

Radial ball bearings made of metal, ceramics and plastics are commonly used as important components in various types of industrial machinery. Due to the latest markets demands for elements capable of withstanding e.g. corrosive environment, metallic bearings are being gradually replaced by components produced from high performance engineering plastic polymers. In order to investigate the failure mechanism of polymer bearings and further improve their performance in practical applications in an underwater environment, in this research crack propagation in Poly-ether-ether-ketone (PEEK) was studied by rolling contact fatigue (RCF) testing under water. Crack propagation in the inner ring raceway surface and subsurface areas of PEEK bearings after testing was observed by a laser confocal microscope. Cracks and flaking failure were found on the bearing raceway surface. From the RCF tests results, it was found that the detected cracks could be divided into three groups: Main Surface Cracks, Semi-circular Cracks and Main Subsurface Cracks. It is concluded that flaking occurs on the inner ring raceway due to the fusion of semi-circular cracks and a main subsurface crack.

Investigating the Mechanical Property and Rolling Contact Fatigue Life of Diamond-Like Carbon Films on Bearing Steel

2008 ◽  
Vol 575-578 ◽  
pp. 990-995 ◽  
Author(s):  
Hong Xi Liu ◽  
Ye Hua Jiang ◽  
Rong Zhou ◽  
Zu Lai Li ◽  
Bao Yin Tang
Keyword(s):  
Steel Substrate ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Bearing Steel ◽  
Carbon Films ◽  
Rolling Contact ◽  
Diamond Like Carbon ◽  
Spectroscopy Analysis ◽  
Treated Sample ◽  
Contact Fatigue Life

Microstructure and properties of plasma immersion ion implantation and deposition diamond-like carbon (DLC) films on bearing steel substrate were studied. Raman spectroscopy analysis indicates that PIII&D DLC consists of a mixture of amorphous and crystalline phases, with a variable ratio of sp2/sp3 carbon bonds, and the sp3 bonds content more than 10%. The nanohardness (H) and the elastic modulus (E) of DLC films measurement indicate that the maximum H (E) value is 40GPa (430GPa). The corrosion polarization curves prove that the corrosion resistance of DLC samples is much better than that of substrate. The friction and wear behaviors and rolling contact fatigue (RCF) life of these samples show that the friction coefficient decrease from 0.87 to 0.2; the L10 , L50 , La and L life of treated sample increases by 9.1, 3.2, 2.5 and 2.4 times, respectively. The RCF life scatter extent of treated samples is improved significantly.

Influence of Radial Load on PEEK Plastic Bearings Life Cycle under Water Lubricated Conditions

2011 ◽  
Vol 217-218 ◽  
pp. 1260-1265 ◽  
Author(s):  
Hitonobu Koike ◽  
Takashi Honda ◽  
Katsuyuki Kida ◽  
Edson Costa Santos ◽  
Justyna Rozwadowska ◽  
...  
Keyword(s):  
Feed Rate ◽  
High Performance ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Wear Loss ◽  
Ball Bearings ◽  
Before And After ◽  
Dry Conditions ◽  
Market Needs

Radial ball bearings made of metal, ceramics and plastics are commonly used as important components in industrial machinery. Usage of high performance engineering plastic polymers is increasing progressively as a replacement for metal components due to the latest markets demands. Poly-ether-ether-ketone (PEEK) is a promising material for precision-machined custom bearings, products that are expected to suit special market needs. In the present study, PEEK radial ball bearings were manufactured by lathe machining under different parameters and their rolling contact fatigue (RCF) resistance under water lubricated conditions was investigated. We observed the surface of the bearings prior and after testing by laser confocal microscope. The wear loss was measured by weighing the bearings before and after test. Cracks and/or flaking failures were identified on the bearing surface after testing. From the RCF tests results, we found that, at water lubricated conditions, crack initiation occurred later in the material that was machined at slower feed rate while at dry condition, the feed rate had little influence on the wear loss and cracking. Wear loss in the case of bearings tested under water was much less severe than that of bearings tested at dry conditions.

Surface Densification Coupled with Higher Density Processes Targeting High-Performance Gearing

2007 ◽  
Vol 534-536 ◽  
pp. 317-320 ◽  
Author(s):  
Francis Hanejko ◽  
Arthur Rawlings ◽  
Patrick King ◽  
George Poszmik
Keyword(s):  
High Performance ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
High Strength ◽  
Rolling Contact ◽  
Powder Metal ◽  
Surface Densification ◽  
Performance Requirements ◽  
Fatigue Durability ◽  
Steel Grades

This paper will describe a powder and processing method that facilitates single presssingle sintered densities approaching 7.5 g/cm³. At this sintered density, mechanical properties of the powder metal (P/M) component are significantly improved over current P/M technologies and begin to approach the performance of wrought steels. High performance gears have the added requirement of rolling contact fatigue durability that is dependent upon localized density and thermal processing. Combining high density processing of engineered P/M materials with selective surface densification enables powder metal components to achieve rolling contact fatigue durability and mechanical property performance that satisfy the performance requirements of many high strength automotive transmission gears. Data will be presented that document P/M part performance in comparison to conventional wrought steel grades.

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