scholarly journals Modeling research on laser quenching process of GCr15 bearing steel basing on material properties obtained with experimental methods

Author(s):  
Zhiqiang Li ◽  
Zhi Wen ◽  
Fuyong Su
2007 ◽  
Vol 201 (15) ◽  
pp. 6615-6618 ◽  
Author(s):  
Tao Sun ◽  
Langping Wang ◽  
Yonghao Yu ◽  
Yuhang Wang ◽  
Xiaofeng Wang ◽  
...  

2013 ◽  
Vol 486 ◽  
pp. 205-210
Author(s):  
Zuzana Lašová ◽  
Robert Zemcik

This work is focused on identification of material properties of piezoelectric patch transducers used e.g. for structural health monitoring before attaching to the substrate structure. Two experimental methods were concerned. At first two piezoelectric patches were supplied with a pair of collocated strain gauge rosettes. Both transducers were actuated with the same periodical signal. Significant difference in the results for two transducers was found, however it was claimed to be within tolerance by the producer. As an alternative method a measurement in an optical microscope was chosen. The patch was clamped at one side and actuated by a voltage signal. The displacement of the free end was captured by the microscope and processed in a graphical editor. Finally, a finite element model of the transducer was created and its material data were obtained by calibration with experimental data.


Author(s):  
Qianren Tian ◽  
Guocheng Wang ◽  
Xinghu Yuan ◽  
Qi Wang ◽  
Seetharaman Sridhar

Nitride and carbide are the second phases which play an important role in the performance of bearing steel, and their precipitation behavior is complicated. In this study, TiN-MCx precipitations in GCr15 bearing steels were obtained by non-aqueous electrolysis, and their precipitation mechanisms were studied. TiN is the effective heterogeneous nucleation site for Fe7C3 and Fe3C, therefore, MCx can precipitate on the surface of TiN easily, its chemistry component consists of M3C and M7C3 (M = Fe, Cr, Mn) and Cr3C2. TiN-MCx with high TiN volume fraction, TiN forms in early stage of solidification, and MCx precipitates on TiN surface after TiN engulfed by the solidification advancing front. TiN-MCx with low TiN volume fraction, TiN and MCx form in late stage of solidification, TiN can not grow sufficiently and is covered by a large number of precipitated MCx particles.


Author(s):  
Mohamed Kchaou ◽  
Amira Sellami ◽  
Jamal Fajoui ◽  
Recai Kus ◽  
Riadh Elleuch ◽  
...  

This article describes and explains the tribological tests and methods for the evaluation of the performance of the brake friction materials. It starts by discussing the particularities of these materials and the variation of characterization tests, which can experimentally simulate many aspects of brake situation but with a large field of tribo-test, from standard to specific protocol. Examples of preparation, procedures, instrumentation, and analysis results for the tribological aspect testing ranging from the scale of vehicle braking performance (by methods including inertia dynamometers, Krauss testing, friction assessment screening test, and Chase testing) to simplified test using reduced-scale prototypes for small-sample friction, are explained. A particular attention is attributed to the discussion of the viability of the friction coefficient report in relation to the material properties and brake compound performance. At the end of this article, the guarantee of the performance output or ranking evaluated by such experimental methods is discussed.


2012 ◽  
Vol 562-564 ◽  
pp. 350-354
Author(s):  
Jian Hua Fang ◽  
Jiu Wang ◽  
Jiang Wu ◽  
Bo Shui Chen ◽  
Ling Dong

A N-containing additive, amide type modified rapeseed oil (named as NRO), was prepared by chemical modification of rapeseed oil and characterized by infrared spectrum The friction and wear performances of AZ91D magnesium alloy against GCr15 bearing steel under the lubrication of rapeseed oil formulated with NRO were evaluated on a SRV tribotester. The topographies and the chemical species of the worn surfaces of magnesium alloy were analyzed by a scanning electron microscope (SEM) and an X-ray photoelectron spectroscope (XPS), respectively. The results indicated that the friction and wear of the magnesium alloy—steel tribomates could be effectively reduced by formulating NRO into rapeseed oil lubricant. The friction coefficients and the wear volumes of magnesium alloy decreased with increasing contents of NRO. The surface lubricated with NRO-doped rapeseed oil was characterized by less wear as compared with that lubricated with neat rapeseed oil. The enhanced anti-wear and friction-reducing abilities of rapeseed oil by NRO in the lubrication of magnesium alloy against steel were ascribed to the formation of a composite boundary lubrication film due to the strong adsorption of NRO and rapeseed oil onto the lubricated surfaces and their tribochemical reactions with magnesium alloy.


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