There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Thermal crack growth-based fatigue life prediction due to braking for a high-speed railway brake disc

Investigating the effect of SiC particles on the physical and thermal properties of Al6061/SiCp composite

24CrNiMo alloy steel used for brake disc was prepared by selective laser melting technology with the processing parameters of high power input and thicker powder layer. The Microstructure and mechanical properties of as-fabricated part were characterized. Effects of processing parameters on the production efficiency, thermal history and microstructure evolution mechanism were studied. The results of this work indicate that the as-fabricated steel microstructure mainly consist of granular bainite and meta bainite, which results in a high microhardness and fine strength. High laser power input leads to a high thermal accumulation level in a SLM process and the microstructure mainly transforms into bainite. In addition, compared to the commonly used parameters, the overall preparation efficiency in this study is enhanced by 82.9%. These presented results provide an insight on how to improve SLM efficiency, and preparation of high-performance 24CrNiMo alloy steel by SLM technology shows high potential for manufacturing of the brake disc core part.

Selective laser melting of 24CrNiMo steel for brake disc: Fabrication efficiency, microstructure evolution, and properties

Disc brake system is one of the most critical components in a vehicle, which is always exposed to nonlinear transient thermoelastic conditions. Optimal design of a brake system to suit the heat transfer, weight and packing requirements is an ongoing challenge. Substantial researches have been carried out and are underway, in order to address the diverse issues related to thermal, mechanical and structural performances of automobile disc brakes. With the extensive application of numerical tools and techniques, the analyses involved became easier and effective. The present article provides an exhaustive review of the numerical and experimental studies reported so far, on the analysis and design of solid and ventilated disc brakes. The directions for future works are also described. The review reveals that, there is enough scope for extended research for realizing optimal design of disc brake system by truly emulating all the relevant practical situations.

Thermo-Mechanical and Structural Performances of Automobile Disc Brakes: A Review of Numerical and Experimental Studies

Analyzing the mechanisms of fatigue crack initiation and propagation in CRH EMU brake discs

The effect of braking energy on the fatigue crack propagation in railway brake discs

Low cycle fatigue behavior of Cr–Mo–V low alloy steel used for railway brake discs

Due to the low density and high temperature resistance, the SiCp/A356 composites have great potential for weight reduction and braking performance using the brake disc used in trains and automobiles But the friction coefficient and braking performance are not stable in the braking process because of temperature rising In this paper, friction and wear behaviors of SiCp/A356 composite against semimetallic materials were investigated in a ring-on-disc configuration in the temperature range of 30°C to 300°C Experiments were conducted at a constant sliding speed of 14 m/s and an applied load of 200 N Worn surface, subsurface, and wear debris were also examined by using SEM and EDS techniques The third body films (TBFs) lubricated wear transferred to the third body abrasive wear above 200°C, which was a transition temperature The friction coefficient decreased and weight of semimetallic materials increased with the increase of temperature and the temperature had almost no effect on the weight loss of composites The dominant wear mechanism of the composites was microploughing and slight adhesion below 200°C, while being controlled by cutting grooves, severe adhesion, and delamination above the 200°C

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Temperature Effects on the Friction and Wear Behaviors of SiCp/A356 Composite against Semimetallic Materials

The thermal fatigue crack initiation and propagation behavior of SiCp/A356 composites which is produced by stirring casting were studied. Specimens with a V-shaped notch were used in the thermal fatigue experiment. Optical microscope (OM) and scanning electron microscope (SEM) were used to observe the crack growth. Crack initiated at the notch tip after about 150 cycles of heating and cooling from room temperature to 250 °C. The crack propagation stage was dominated during the whole crack growth. Cracks mainly propagated along the interface of particle and through the matrix. The propagation stage experienced the cycle of slow propagation and fast propagation, and a Step-Like shape was observed during the crack growth process. The micro cracks appeared in the interface of particle and the matrix after repeated thermal cycles, and induced fast propagation by coalescing with the main cracks. Distributions of the particle play an important role in hindering thermal fatigue crack propagation. Hardness of the composites decreased with the increase of the number of cycles, and decreased by 46.1% after thermal 290 cycles.

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Papers

Analyzing the mechanisms of fatigue crack initiation and propagation in CRH EMU brake discs

The effect of braking energy on the fatigue crack propagation in railway brake discs

Low cycle fatigue behavior of Cr–Mo–V low alloy steel used for railway brake discs

Temperature Effects on the Friction and Wear Behaviors of SiCp/A356 Composite against Semimetallic Materials

Thermal fatigue crack behavior of SiCp/A356 composites prepared by stirring casting