Technological Surface Layer Selection for Small Module Pitches of Gear Wheels Working under Cyclic Contact Loads

2006 ◽  
Vol 513 ◽  
pp. 69-74 ◽  
Author(s):  
Z. Gawroński ◽  
J. Sawicki
Keyword(s):  
Surface Layer ◽  
Residual Stresses ◽  
Gear Wheel ◽  
X Ray ◽  
Fem Method ◽  
Contact Loads ◽  
Selection For ◽  
Gear Wheels ◽  
External Loads ◽  
Selection Of

Selection of proper technological surface layer well resistant to cyclic external loads superposed onto residual stresses is presented in this paper, with a gear wheel taken as an example. The computer simulations of external loads were carried out by means of the FEM method (Finite Element Method) with the use of the ANSYS package. Residual stresses were measured by means of the Waisman-Philips and modified X-ray sin2Ψ method. The results of the stress superposition were verified experimental by with use of a circulating power stand. The applied low pressure nitiriding method NITROVAC demonstrated a high ability to increase the durability and reliability of the discussed toothed wheel in comparison with the convencional treatment applied so far.

X-Ray Diffraction Analysis of Steel with Oxidised Surface Layer

2016 ◽  
Vol 368 ◽  
pp. 99-102
Author(s):  
Lukáš Zuzánek ◽  
Ondřej Řidký ◽  
Nikolaj Ganev ◽  
Kamil Kolařík
Keyword(s):  
Residual Stress ◽  
Surface Layer ◽  
Residual Stresses ◽  
Diffraction Analysis ◽  
Oxide Surface ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electrolytic Polishing ◽  
Small Depth

The basic principle of the X-ray diffraction analysis is based on the determination of components of residual stresses. They are determined on the basis of the change in the distance between atomic planes. The method is limited by a relatively small depth in which the X-ray beam penetrates into the analysed materials. For determination of residual stresses in the surface layer the X-ray diffraction and electrolytic polishing has to be combined. The article is deals with the determination of residual stress and real material structure of a laser-welded steel sample with an oxide surface layer. This surface layer is created during the rolling and it prevents the material from its corrosion. Before the X-ray diffraction analysis can be performed, this surface layer has to be removed. This surface layer cannot be removed with the help of electrolytic polishing and, therefore, it has to be removed mechanically. This mechanical procedure creates “technological” residual stress in the surface layer. This additional residual stress is removed by the electrolytic polishing in the depth between 20 and 80 μm. Finally, the real structure and residual stresses can be determined by using the X-ray diffraction techniques.

Residual Stresses in Locally Long Fiber Reinforced Aluminum Parts

2011 ◽  
Vol 284-286 ◽  
pp. 284-292 ◽  
Author(s):  
Shao Chun Sun ◽  
Zhi Yuan Chen ◽  
Qiang Wu ◽  
De Xin Ma ◽  
Yu Tao Zhao
Keyword(s):  
Residual Stress ◽  
Aluminum Alloy ◽  
Residual Stresses ◽  
Tensile Residual Stress ◽  
Fiber Reinforced ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fem Method ◽  
The Matrix ◽  
Compressive Residual Stresses

In locally long fiber reinforced aluminum parts two types residual stresses exist. They are the microscopic residual stress between fiber and matrix and the macroscopic residual stress between reinforced and unreinforced zones. The residual stresses between fiber and matrix in γ-Al2O3 long fiber reinforced aluminum alloy Al-6-1-1 were measured with X-ray Diffraction process as well as simulated with FEM method. The results indicated that the residual stresses in both fiber and matrix were distributed very unequally. The maximum tensile residual stress occurred at the boundary in the matrix and the maximum compressive residual stresses occurred near the boundary in the fiber. The macroscopic residual stresses between the reinforced and unreinforced zones were also measured with borehole method as well as simulated with FEM. It was found that the macroscopic residual stresses at most locations in both the reinforced and unreinforced zones were not harmfully high. However in both reinforced and unreinforced zones there were small sub-zones of very large tensile residual stresses.

scholarly journals ПОДВІЙНА ХІМІКО-ТЕРМІЧНА ОБРОБКА ЗУБЧАСТОГО КОЛЕСА ІЗ СТАЛІ ВКС-5

2018 ◽  
pp. 81-85
Author(s):  
Андрей Борисович Единович ◽  
Александр Владимирович Колоколов ◽  
Андрей Сергеевич Турейский
Keyword(s):  
Surface Layer ◽  
Thermal Treatment ◽  
Surface Deformation ◽  
Gear Wheel ◽  
Heat Resistant Steel ◽  
Gas Nitriding ◽  
Compressive Stresses ◽  
Secondary Hardness ◽  
Contact Durability ◽  
Gear Wheels

The process of the double chemical-thermal treatment (DCTT) a gear made of heat-resistant steel VKS-5 is quite common and makes it possible to obtain secondary hardness. Double or combined chemical-thermal treatment is designed to increase the contact durability of steels by nitriding final finished parts that these were carburizing, hardened and ground. Comparison of the process of double chemical-thermal treatment with traditional methods of chemical-thermal treatment(CTT) carburizing and nitriding. Object of the study is a gear wheel treated with the DCTO method, after it was compared the hardness of the wheel past the DCTO using gas nitriding and liquid, with other similar CTT processes such as nitriding and carburizing and nitrocarburizing the results were a graph of hardness and the depth of the strengthened layer for each of the processes. Discussion of the developed technology for the preparation of double chemical-thermal treatment and the results of studies on the use of dispensing methods for obtaining DCTO. Efficiency is justified by metallographic studies of the developed technology. Also, metallographic studies have shown the need to control the surface layer the E-phase is formed due to which it is possible to substantially increase the hardness of the surface while preserving the structure of the entire material without cracking thereby providing increased contact durability. We also consider the possibility of using ion-plasma equipment, which allows to significantly increase the speed of the process, control the thickness of the layer of surface phases and also makes it possible to additionally apply the method of surface deformation to create compressive stresses on the surface. This technology allows to obtain a surface combining the advantages of nitriding and carburizing, excluding useing harmful substances affecting a health and ecology, and also economically more beneficial than nitrocarburizing. DCTT can be used to increase the contact endurance of the gear wheels in a large module, and eliminating the need for further machinary treatment of the surface layer after DCTT.

Determination of residual macrostresses in surface layer of solid-rolled railway wheels disks by X-ray diffractometry

2020 ◽  
pp. 567-571
Author(s):  
I.G. Roberov ◽  
D.B. Matveev ◽  
A.Yu. Bespamyatnykh ◽  
V.S. Grama ◽  
M.A. Kiselev ◽  
...  
Keyword(s):  
Surface Layer ◽  
Stress State ◽  
Residual Stresses ◽  
Rolled Steel ◽  
X Ray ◽  
Compressive Stresses ◽  
Surface Residual Stresses ◽  
Residual Macrostresses ◽  
Railway Wheels

Residual stresses on the surface of disks of one-piece-rolled steel railway wheels, caused by their fi nishing (turning) with different tool feed rate and speed, are measured using the X-ray diffractometric method implemented using the DRP portable diffractometer. It is shown that the specifi ed fi nishing parameters have signifi cant infl uence on the level of surface residual stresses induced by fi nishing. The most favorable stress state (compressive stresses up to –200 MPa) on the surface of the disks is achieved under relatively small values of tool feed and speed. The results may serve as basis for improving of the fi nishing technology of solid-rolled wheels.

Identifying Measurement Invariant Item Sets in Cross-Cultural Settings Using an Automated Item Selection Procedure

Methodology ◽  
2018 ◽  
Vol 14 (4) ◽  
pp. 177-188 ◽  
Author(s):  
Martin Schultze ◽  
Michael Eid
Keyword(s):  
Measurement Invariance ◽  
Optimal Solution ◽  
Selection Procedure ◽  
Cross Cultural ◽  
Item Selection ◽  
Ant System ◽  
Item Quality ◽  
Ant System Algorithm ◽  
Selection For ◽  
Selection Of

Abstract. In the construction of scales intended for the use in cross-cultural studies, the selection of items needs to be guided not only by traditional criteria of item quality, but has to take information about the measurement invariance of the scale into account. We present an approach to automated item selection which depicts the process as a combinatorial optimization problem and aims at finding a scale which fulfils predefined target criteria – such as measurement invariance across cultures. The search for an optimal solution is performed using an adaptation of the [Formula: see text] Ant System algorithm. The approach is illustrated using an application to item selection for a personality scale assuming measurement invariance across multiple countries.

ESTIMASI NILAI HERITABILITAS BOBOT IKAN MAS VARIETAS PUNTEN DALAM PROGRAM SELEKSI INDIVIDU

2016 ◽  
Vol 11 (3) ◽  
pp. 217
Author(s):  
Estu Nugroho ◽  
Budi Setyono ◽  
Mochammad Su’eb ◽  
Tri Heru Prihadi
Keyword(s):  
Body Weight ◽  
Selection Response ◽  
Base Population ◽  
Breeding Programs ◽  
Male And Female ◽  
Body Weight Trait ◽  
Population Selection ◽  
Selection For ◽  
Weight Trait ◽  
Selection Of

Program pemuliaan ikan mas varietas Punten dilakukan dengan seleksi individu terhadap karakter bobot ikan. Pembentukan populasi dasar untuk kegiatan seleksi dilakukan dengan memijahkan secara massal induk ikan mas yang terdiri atas 20 induk betina dan 21 induk jantan yang dikoleksi dari daerah Punten, Kepanjen (delapan betina dan enam jantan), Kediri (tujuh betina dan 12 jantan), Sragen (27 betina dan 10 jantan), dan Blitar (15 betina dan 11 jantan). Larva umur 10 hari dipelihara selama empat bulan. Selanjutnya dilakukan penjarangan sebesar 50% dan benih dipelihara selama 14 bulan untuk dilakukan seleksi dengan panduan hasil sampling 250 ekor individu setiap populasi. Seleksi terhadap calon induk dilakukan saat umur 18 bulan pada populasi jantan dan betina secara terpisah dengan memilih berdasarkan 10% bobot ikan yang terbaik. Calon induk yang terseleksi kemudian dipelihara hingga matang gonad, kemudian dipilih sebanyak 150 pasang dan dipijahkan secara massal. Didapatkan respons positif dari hasil seleksi berdasarkan bobot ikan, yaitu 49,89 g atau 3,66% (populasi ikan jantan) dan 168,47 g atau 11,43% (populasi ikan betina). Nilai heritabilitas untuk bobot ikan adalah 0,238 (jantan) dan 0,505 (betina).Punten carp breeding programs were carried out by individual selection for body weight trait. The base population for selection activities were conducted by mass breeding of parent consisted of 20 female and 21 male collected from area Punten, eight female and six male (Kepanjen), seven female and 12 male (Kediri), 27 female and 10 male (Sragen), 15 female and 11 male (Blitar). Larvae 10 days old reared for four moths. Then after spacing out 50% of total harvest, the offspring reared for 14 months for selection activity based on the sampling of 250 individual each population. Selection of broodstock candidates performed since 18 months age on male and female populations separately by selecting based on 10% of fish with best body weight. Candidates selected broodstocks were then maintained until mature. In oder to produce the next generation 150 pairs were sets and held for mass spawning. The results revealed that selection response were positive, 49.89 g (3.66%) for male and 168.47 (11.43%) for female. Heritability for body weight is 0.238 (male) and 0.505 (female).

Utilisation of High-Energy Heat Sources in Magnesium Alloy Surface Layer Treatment

2013 ◽  
Vol 58 (2) ◽  
pp. 619-624 ◽  
Author(s):  
M. Szafarska ◽  
J. Iwaszko ◽  
K. Kudła ◽  
I. Łegowik
Keyword(s):  
Surface Layer ◽  
Magnesium Alloy ◽  
Physicochemical Properties ◽  
Treatment Effectiveness ◽  
High Energy ◽  
Alloy Surface ◽  
Heat Sources ◽  
X Ray ◽  
Additional Equipment ◽  
Alloy Surface Layer

The main aim of the study was the evaluation of magnesium alloy surface treatment effectiveness using high-energy heat sources, i.e. a Yb-YAG Disk Laser and the GTAW method. The AZ91 and AM60 commercial magnesium alloys were subject to surface layer modification. Because of the physicochemical properties of the materials studied in case of the GTAW method, it was necessary to provide the welding stand with additional equipment. A novel two-torch set with torches operating in tandem was developed within the experiment. The effectiveness of specimen remelting using a laser and the GTAW method was verified based on macro- and microscopic examinations as well as in X-ray phase analysis and hardness measurements. In addition, the remelting parameters were optimised. The proposed treatment methodology enabled the achieving of the intended result and effective modification of a magnesium alloy surface layer.

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