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.

Mechanical Behaviour of Al7075 Hybrid Composites Developed through Squeeze Casting

The automotive and aerospace sector are behind the development of squeeze casting process, as the squeeze cast components exhibit improved mechanical properties. Squeeze casting is a hybrid metal processing technique that combines the advantage of both casting and forging in one operation. The aluminium alloy 7075 is a futuristic material that is widely used to produce automotive and aerospace components. Cylindrical component of AL 7075 was produced by varying the squeeze pressure at certain level. The specimen was made from the component as per ASTM standard and they were tested for mechanical properties such as tensile hardness and impact strength respectively. It was found that mechanical properties were enhanced with increase in squeeze pressure. The aluminium 7075 hybrid composites developed through squeeze casting is fabricated and experimented upon and found to have adequate potential for wide variety of application. In aerospace industries it can be used in gear components, blade sleeves, guide vanes, wing components etc. Applications in surface transport are brake rotors, automotive engine cylinder, engine exhaust valve, body chassis and connecting rods. This material can be used in light weight applications such as power lines and wind mill fans.

Calculation of strength, rigidity, and stability of the aircraft fuselage frame made of composite materials

Carbon-carbon composite materials (CCCM) are characterized by high heat resistance and thermostability for which they, in most of their physical and mechanical characteristics, can be attributed to the most promising materials. Approximately 81% of all carbon-carbon composite materials are used for the manufacture of brake rotors for aircraft, 18% – in space rocket technology, and only 1% – for all other areas of application. This study discusses calculations of the strength, rigidity, and stability of a frame made of carbon-carbon composite materials. It is known that the strength of CCCM based on high-strength carbon fibers is higher than the strength of a composite material based on high-modulus carbon fibers obtained at various processing temperatures. The stress-strain behaviour (SSB) of the material is carried out. Among the special properties of CCCM are low porosity, low coefficient of thermal expansion, maintaining a stable structure and properties, as well as product dimensions.

Laser Cladding Treatment for Refurbishing Disc Brake Rotors: Environmental and Tribological Analysis

In this study, grey cast iron disc brake rotors are refurbished by adding a surface layer through laser cladding. Current methods to deal with replaced rotors mainly include remelting, with a minority fraction disposed in landfill. Both approaches result in a huge waste of resources and an increase in CO2 footprint. From a sustainable point of view, this study aims to evaluate the feasibility of refurbishing brake rotors by a combined environmental and tribological performance approach. A streamlined life cycle assessment is conducted to compare the environmental impacts between producing virgin grey cast iron brake rotors and refurbishing replaced brake rotors by laser cladding. It turns out that the energy consumption and CO2 footprint of the laser cladding refurbished brake rotors are 80% and 90% less than the virgin brake rotors. The results show that the refurbished brake rotor yields higher friction compared to the original cast iron utilizing the same pad material. The wear and particle emissions of the disc brake contact are in this study higher for the laser-cladded one compared to the original cast iron one.

Laser cladding treatment for refurbishing disc brake rotors – environmental and tribological analysis

In this study, grey cast iron disc brake rotors are refurbished by adding a surface layer through laser cladding. Current methods to deal with replaced rotors mainly include re-melting, with a minority fraction disposed in landfill. Both approaches result in a huge waste of resources and an increase in CO 2 footprint. From a sustainable point of view, this study aims to evaluate the feasibility of refurbishing brake rotors by a combined environmental and tribological performance approach. A streamlined life cycle assessment is conducted to compare the environmental impacts between producing virgin grey cast iron brake rotors and refurbishing replaced brake rotors by laser cladding. It turns out that the energy consumption and CO 2 footprint of the laser cladding refurbished brake rotors are 80% and 90% less than the virgin brake rotors. The results show that the refurbished brake rotor yields higher friction compared to the original cast iron utilizing the same pad material. The wear and particle emissions of the disc brake contact are in this study higher for the laser cladded one compared to the original cast iron one.

Fault Detection and Isolation for Brake Rotor Thickness Variation

Brake rotors are critical parts of the disc braking system for modern vehicles. One common failure for brake rotors is the thickness variation, which may result in unpleasant brake pulsation, vehicle vibration during braking, or eventually lead to the malfunction of the braking system. In order to improve customer satisfaction, vehicle serviceability and availability, it is necessary to develop an onboard fault detection and isolation solution. In our previous work, the vibration features of master cylinder pressure, vehicle longitudinal acceleration and wheel speed were identified as fault signatures. Based on these fault signatures, a vibration- based fault detection and isolation algorithm is developed in this work. The difference of frequency response between the braking period and the normal driving period (non-braking) is employed to improve the algorithm robustness. The experiment results demonstrate the proposed algorithm can robustly diagnose the thickness variation fault and isolate the fault to each vehicle corner.

INVESTIGATION OF NOISE CHARACTERIZATION OF COATED ROTORS

In this study, four excessive worn brake rotors of a light commercial vehicle are coated using different thickness, methods and powder coatings. Coated rotors ([Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text]) compared with OEM brake rotor ([Formula: see text]0) in terms of friction coefficient ([Formula: see text]) and braking noise. Three braking test procedures (bedding, hot judder I and II) are applied to five rotors using inertia brake dynamometer. Results in bedding testing procedures showed that [Formula: see text] rotor provided higher brake noise and higher [Formula: see text] compared with coated rotors. In hot judder I testing procedures, [Formula: see text] rotor provided higher [Formula: see text] and higher brake noi0se compared with the other coated rotors and [Formula: see text]. Also, in hot judder II testing procedures, [Formula: see text] rotor provided higher [Formula: see text] compared with the other rotors, [Formula: see text] provided higher brake noise compared with the other coated rotors. In addition, based on experimental data, noise levels are estimated by multiple regression method with dummy variables.

AlSi-SiC Composites for Automotive Brake Rotor

This manuscript investigates the Fabrication and Microstructure of Automotive Brake Rotor Made of AlSi-SiC Composites. This work is oriented toward fabrication of automotive brake rotors from Al-9Si and Al-12Si reinforced with 10 and 20% SiC particles using stir-casting method. The brake rotors were subjected to heat treatment. Aging behavior showed that hardness increased with the addition of SiC reinforcements by 104%, comparing to solution treatment condition. Also, the addition of SiC particles accelerates formation of precipitates. Microstructure of brake rotors made of composite revealed uniform distribution of SiC particles, primary phase (⍺-Al) and modified eutectic Si. EDX analysis showed the presence of Al, Mg and O at the interface between matrix and SiC particles.