Review of the coatings used for brake discs regarding their wear resistance and environmental effect

Wear of a friction pair of brake (brake disc and pads), in addition to reducing the active safety of vehicles, leads to the formation of particles that can affect the environment and human health. In addition to the technologies that are being developed for the collection of particles created by the wear of brakes during braking process, today new materials are being introduced, as well as various technologies for processing friction pairs with the aim of reducing brake wear and thus the formation of particles. Furthermore, today, technologies for coating (cladding) the friction surfaces of disc brakes with some materials are increasingly applied and researched, in order to reduce the wear intensity (wear rate) of disc brakes, i.e. the emission of particles created by wear of friction pairs. The aim of this paper is to analyse and review different deposition techniques and materials used for brake discs coatings, as well as the effect it has on the wear rate of friction pair. There are many coating deposition techniques, and special attention is paid to the technology of laser hardfacing of brake rotors.

Thermal Analysis of a Disc

The disk brakes are special mechanized parts in a vehicle attached with the tires to help reduce the velocity of the vehicle. As the brake pads caused friction with the disc brakes, there is a temperature rise. Due to this there are great chances of disc brake’s failure if temperature rises above some permissible limit. Solidworks and ANSYS are the design and analysis tools which are used to accomplish this project. The disc brake was designed using Solidworks and it was analysed in ANSYS workbench. The main aim of this project is to analyse two-disc brakes manufactured with different materials to compare their properties and select one with most benefits. Keywords: ANSYS, FEA, Disc brake, Thermal analysis, braking system, Radiation.

Mechanical and Dynamic Maps of Disc Brakes under Different Operating Conditions

The operating conditions during the braking process in an automobile affect the tribological contact between the pad and disc brake, thus, influencing the times and distances of braking and, in a more significant way, the safety of the braking process. This mathematical work aimed to provide a general visualization of the disc brake’s mechanical, dynamic, and thermal behavior under different operating conditions through 2D maps of the power dissipated, braking time, and braking distance of a disc brake with a ventilation blade N- 38 type. However, the dissipated energy on the disc brake in terms of temperature was analyzed considering Newton’s cooling law and mathematical calculations through classical theories of the dynamic and mechanical behavior of the disc brakes. For this purpose, the Response Surface Methodology (RSM) and Distance Weighted Least Squares (DWLS) fitting model considered different operating conditions of the disc brake. The results demonstrate that the disc brakes can be used effectively in severe operational requirements with a speed of 100 km/h and an ambient temperature of 27 °C, without affecting the occupant’s safety or the braking system and the pad. For the different conditions evaluated, the instantaneous temperature reaches values of 182.48 and 82.94 °C, where the high value was found for a total deceleration to 100 km/h to 0, which represent a total braking distance of around 44.20 to 114.96 m depending on the inclination angle (θ). Furthermore, the energy dissipation in the disc brakes depends strongly on the disc, blades and pad geometry, the type of material, parameters, and the vehicle operating conditions, as can be verified with mathematical calculation to validate the contribution of the effectiveness of the braking process during its real operation.

Modeling the Average and Instantaneous Friction Coefficient of a Disc Brake on the Basis of Bench Tests

This article presents the results of tests conducted on the average and instantaneous friction coefficients of railway vehicle disc brakes. The tests were carried out independently of various states of wear on the friction linings and the brake disc. The requirements of the International Union of Railways (UIC) regarding the approval of brake linings for use were taken into account. Based on many years of research using a brake bench to test railway disc brakes, the authors developed multiple regression models for the average friction coefficient and fluctuations (tolerances) in the instantaneous friction coefficient and achieved 870 results. The models proposed three types of variables: the input braking parameters (speed, pressure, and mass to be braked), operational parameters (the wear on the friction linings and the brake disc), and design parameters (perforations in the form of holes on the disc surface). The above two models were validated on the basis of 384 brakes, and in subsequent stages a further evaluation was performed. The coefficients were determined to be, respectively, 0.99 for the model of the average friction coefficient and 0.71 for the model of tolerance (fluctuations) of the instantaneous friction coefficient.

Elemental analysis of particles emitted from aircraft using in-vacuum PIXE

To comprehend the elemental characterization of the particles emitted from an aircraft, we performed element analysis using in-vacuum PIXE for particles emitted from the carbon disc brakes and tires in addition to the exhaust particles produced by the jet engine. As for the elemental characteristics of aircraft source particulate matter, engine reversers mainly consisted of Al, Si, Ca, and Fe, and also included Ti, Cr, Mo, and W. The disc brakes mainly contained Si, Ca, and Fe, and also contained S, K, Ti, Cr, Ni, and Cu. In tires, Na, Al, Si, Ca, Fe, and Zn were mainly found, and S, K, and Ti were also detected. Thus, there was a difference in the trace elements found in the aircraft source particulate matter. These results aid in determining the component features of particles emitted from an aircraft.

FEA Analysis and Design Optimization of Disk Brake

The disc brakes are vital components of vehicle for retarding its velocity. The proper design of disk brake is essential in dissipating heat from rubbing surface. The objective of current research is to investigate the thermal characteristics of cast iron disk brake under transient conditions. The designing and FE simulation of brake is conducted using ANSYS software. The existing design is then optimized to determine effect of each optimization variable and also to determine specific design points. The disc brake optimization results have provided significant information on design points at which heat dissipation and temperature is maximum or minimum and the effect of variable on heat flux is also established.

Design and Development of Braking and Wiring Systems in Go-Kart

This paper is aimed to calculate and numerically analyse the effectiveness of Disc brakes before and after manufacturing of full scale Go-kart. Disc brakes are developed over time to time for being a reliable method of decelerating and stopping a vehicle. There are different designs of disk brake systems for various applications. This review gives an in depth description of various geometries of the components and therefore the materials utilized in a disk brake system. In spite of all the involvements, there are still many operational issues associated with disc brakes that need to be understand during operations and resolved. There has been tons of research happening about these issues and at an equivalent time different methods are being proposed to eliminate or reduce them. One major purpose of this paper is to provide a comprehensive overview of all such developments.