Effects of processing parameters on the fracture behaviour of cold roll bonded and accumulative roll bonded Al–Cu lamellar composites

2021 ◽  
pp. 1-11
Author(s):  
Vahid Yousefi Mehr ◽  
Ahmad Rezaeian ◽  
Mohammad Reza Toroghinejad
Keyword(s):  
Fracture Behaviour ◽  
Processing Parameters ◽  
Cold Roll

scholarly journals Surface Performance Multiobjective Decision of a Cold Roll-Beating Spline with the Entropy Weight Ideal Point Method

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
F. K. Cui ◽  
F. Liu ◽  
Y. X. Su ◽  
X. L. Ruan ◽  
S. K. Xu ◽  
...  
Keyword(s):  
Performance Test ◽  
Ideal Point ◽  
Processing Parameters ◽  
Entropy Weight ◽  
Important Indicator ◽  
Spline Surface ◽  
Test Study ◽  
Cold Roll ◽  
Surface Performance ◽  
Object Of Study

Surface performance is an important indicator of the performance of cold roll-beating spline processing. To obtain the best cold roll spline surface performance (surface roughness, residual stress, and surface hardening degree), multiobjective optimal process parameters must be determined. To this end, this paper takes the cold roll-beating spline as the object of study and carries out a cold roll-beating spline surface performance test study. An ideal algorithm for entropy weight is constructed, and the multiobjective decision of the cold roll-beating spline surface performance is determined by using the entropy weight ideal point algorithm, providing a decision on the cold roll-beating spline processing parameters. The grey correlation algorithm is used for verification, and the results show that the multiobjective decision of the cold roll-beating spline surface performance is feasible by using the constructed entropy weight ideal point algorithm.

scholarly journals A Model of Surface Residual Stress Distribution of Cold Rolling Spline

2017 ◽  
Vol 2017 ◽  
pp. 1-21 ◽  
Author(s):  
Z. H. Ding ◽  
F. K. Cui ◽  
Y. B. Liu ◽  
Y. Li ◽  
K. G. Xie
Keyword(s):  
Residual Stress ◽  
Cold Rolling ◽  
High Reliability ◽  
Processing Parameters ◽  
Multiple Regression Model ◽  
Tooth Profile ◽  
Contour Method ◽  
Forming Process ◽  
Surface Residual Stress ◽  
Cold Roll

Residual stress is an important parameter in the evaluation of the performance of a cold rolling spline surface. However, research on cold rolling spline is rare. To improve the surface property of a spline, an involute spline is selected as the object of this study. The contour method for determining cold roll-beating residual stress involves measuring the force spatial distribution, performing a statistical analysis of the experimental results, establishing the parameters for the tooth profile for different positions (dedendum, pitch, and addendum) of residual stress, and determining the effect of pressure on the relationship between stress and the depth of the cold roll-beating. A response surface method is used to establish the spline tooth profile of the dedendum, pitch, and addendum of the residual stress and different depths of the stress layer to obtain the parameters of a multiple regression model and perform a comparative analysis of the experimental and prediction results. Research indicates that the prediction results have high reliability. The establishment of this model has important guiding significance to control the residual stress in the cold roll-beating forming process, optimize the cold roll-beating processing parameters, and improve the surface properties of cold rolling spline.

Laser Surface Coating-Texturing of Cold Roll with Hard Dimples

2008 ◽  
Vol 375-376 ◽  
pp. 364-368
Author(s):  
Da Ping Wan ◽  
Hong Bin Liu ◽  
De Jin Hu ◽  
Hai Feng Wang
Keyword(s):  
Laser Energy ◽  
Sheet Steel ◽  
Laser Pulses ◽  
Processing Parameters ◽  
Bearing Steel ◽  
Experimental Investigations ◽  
3 Dimensional ◽  
Cold Roll ◽  
Laser Coating ◽  
Coated Surfaces

The surface texture of sheet steel plays an important role for automotive applications. To achieve appropriate surface topographies and press-forming behaviour, a new laser coating texturing (LCT) technique aimed at texturing steel work-rolls was proposed. The laser texturing process was realized by applying laser pulses at very high repetition rates to produce innumerable micro-craters with the required shape profile on the surface of the rolls. Moreover, the surface alloying of the dimples was carried out on the substrates of bearing steel GCr15. The submicron WC-Co alloy metal powder was melted into the micro-craters by high laser energy. The effects of processing parameters on the properties of the laser textured samples were investigated. The dimpled surfaces were examined by a 3-dimensional surface profilometer. Microstructures of the coating layers were assessed by optical and scanning electron microscopy. The experimental investigations show that the laser-dimpled hard-coated surfaces exhibit compatible metallurgical interfaces with the substrates. The laser coating textured roll is demonstrated to have excellent abrasion resistance and a much longer service life. The abrasive wear resistance was 5 times higher than that of the substrates. The average surface microhardness values were as high as 700HV.

scholarly journals Surface work-hardening optimization of cold roll-beating splines based on an improved double-response surface-satisfaction function method

2018 ◽  
Vol 10 (6) ◽  
pp. 168781401878263 ◽  
Author(s):  
Fengkui Cui ◽  
Yongxiang Su ◽  
Xiaoqiang Wang ◽  
Xiang Yu ◽  
Xiaolin Ruan ◽  
...  
Keyword(s):  
Response Surface ◽  
Work Hardening ◽  
Function Method ◽  
Processing Parameters ◽  
Function Model ◽  
Satisfaction Function ◽  
Spline Surface ◽  
Cold Roll ◽  
Surface Work ◽  
Double Response

The work hardening of a spline during cold roll-beating is used as an indicator to evaluate the mechanical properties of the surface. To further optimize the work-hardening degree of a cold roll-beating spline surface, weight theory and satisfaction functions are used to improve the double-response surface-satisfaction function model. The model describes the involute spline based on the cold roll-beating speed and feed rate. The generalized reduced-order gradient method is applied to optimize the optimal combination of processing parameters. The experiments validate the optimization results of the improved double-response surface-satisfaction function method and the conventional response surface method based on the cold roll-beating spline test and a comparative analysis of the spline surface metallographic structure. The results show that the satisfaction degree of the improved response model is 0.87384, indicating that the model is robust and reliable. The optimized processing parameters are a cold roll speed of 1448.21 r/mm, a feed rate of 41.71 mm/min, and a degree of work hardening of 144.79%. The spline surface work-hardening degree based on the revised model is higher than that of the conventional model. Thus, the improved double-response surface-satisfaction function model provides better accuracy.

scholarly journals Optimization of the Physical and Mechanical Properties of a Spline Surface Fabricated by High-Speed Cold Roll Beating Based on Taguchi Theory

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Fengkui Cui ◽  
Yongxiang Su ◽  
Shaoke Xu ◽  
Fei Liu ◽  
Guolin Yao
Keyword(s):  
Mechanical Properties ◽  
Feed Rate ◽  
High Speed ◽  
Physical And Mechanical Properties ◽  
Processing Parameters ◽  
Roll Forming ◽  
Surface Residual Stress ◽  
Spline Surface ◽  
Cold Roll ◽  
Reasonable Choice

The aim of this work is to control the physical and mechanical properties of a spline surface and achieve a reasonable choice of high-speed cold roll-beating processing parameters. The surface residual stress and surface work hardening at the indexing circle serve as the main evaluation indices of the physical and mechanical properties of the spline surface. The influence degree of the processing parameters on each evaluation index is analyzed using Taguchi theory. An optimized model for improving the Taguchi process capability index that combines Taguchi theory with entropy theory is established, and the integral process capacity index is optimized via the generalized price reduction gradient method. The results of the optimization and the verification test are implemented in a high-speed cold roll forming test for comparison. The results show that the influence of processing parameters on the physical and mechanical properties of the splash surface of the cold roll can be ordered as follows: feed rate > roll round radius > cold roll-beating speed. In addition, the spline surface physical and mechanical properties of the optimal processing parameters were obtained for the combination of a cold rolling speed of 1581 r/mm, feed rate of 42 mm/min, and roll round radius of 2 mm.

Microstructural Variations in Melt-Spun Rapidly Solidified Ribbons

1985 ◽  
Vol 43 ◽  
pp. 54-55
Author(s):  
L. A. Bendersky ◽  
W. J. Boettinger
Keyword(s):  
Solid State ◽  
Processing Parameters ◽  
Heat Extraction ◽  
Solid State Reactions ◽  
Careful Examination ◽  
Ion Milling ◽  
Melt Spun ◽  
Wheel Side ◽  
Rapidly Solidified ◽  
Heat Extraction Rate

Rapid solidification produces a wide variety of sub-micron scale microstructure. Generally, the microstructure depends on the imposed melt undercooling and heat extraction rate. The microstructure can vary strongly not only due to processing parameters changes but also during the process itself, as a result of recalescence. Hence, careful examination of different locations in rapidly solidified products should be performed. Additionally, post-solidification solid-state reactions can alter the microstructure.The objective of the present work is to demonstrate the strong microstructural changes in different regions of melt-spun ribbon for three different alloys. The locations of the analyzed structures were near the wheel side (W) and near the center (C) of the ribbons. The TEM specimens were prepared by selective electropolishing or ion milling.

Surface Modification and its Influence on the Microstructure and Creep Resistance of Nickel Based Superalloy René 77 / Modyfikacja Powierzchniowa Oraz Jej Wpływ Na Mikrostrukture I Wytrzymałosc Na Pełzanie Odlewów Z Nadstopu Niklu Ren´E 77

2013 ◽  
Vol 58 (1) ◽  
pp. 95-98 ◽  
Author(s):  
M. Zielinska ◽  
J. Sieniawski
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Surface Modification ◽  
Turbine Blades ◽  
Processing Parameters ◽  
Grain Structure ◽  
Creep Tests ◽  
Cobalt Aluminate ◽  
Nickel Based Superalloy ◽  
Average Grain Size

Superalloy René 77 is very wide used for turbine blades, turbine disks of aircraft engines which work up to 1050°C. These elements are generally produced by the investment casting method. Turbine blades produced by conventional precision casting methods have coarse and inhomogeneous grain structure. Such a material often does not fulfil basic requirements, which concern mechanical properties for the stuff used in aeronautical engineering. The incorporation of controlled grain size improved mechanical properties. This control of grain size in the casting operation was accomplished by the control of processing parameters such as casting temperature, mould preheating temperature, and the use of grain nucleates in the face of the mould. For nickel and cobalt based superalloys, it was found that cobalt aluminate (CoAl2O4) has the best nucleating effect. The objective of this work was to determine the influence of the inoculant’s content (cobalt aluminate) in the surface layer of the ceramic mould on the microstructure and mechanical properties at high temperature of nickel based superalloy René 77. For this purpose, the ceramic moulds were made with different concentration of cobalt aluminate in the primary slurry was from 0 to 10% mass. in zirconium flour. Stepped and cylindrical samples were casted for microstructure and mechanical examinations. The average grain size of the matrix ( phase), was determined on the stepped samples. The influence of surface modification on the grain size of up to section thickness was considered. The microstructure investigations with the use of light microscopy and scanning electron microscopy (SEM) enable to examine the influence of the surface modification on the morphology of ’ phase and carbides precipitations. Verification of the influence of CoAl2O4 on the mechanical properties of castings were investigated on the basis of results obtained form creep tests.

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