A study was performed to compare the performance of automotive friction elements, each manufactured with one of two different coke fillers. Coke #1 is a conventional calcined petroleum coke, and coke #2 a proprietary, calcined coke manufactured from a non-petrochemical feedstock. Subject coke materials were fully characterized, physically and chemically. Both coke materials are similar in their respective physical properties, including morphology, hardness, and crush strength. However, there is a significant difference in the trace metal content of the two materials, with coke #1 containing a higher content of sulfur, calcium, iron, nickel, and vanadium than coke #2. Nickel and vanadium are considered potential environmental hazards. Initial friction element evaluation was performed using the J661 Brake Lining Quality Test Procedure (Chase Test). Ultimately each coke material was formulated into two different automotive brake elements.
Design and Simulation Analysis of Braking system for ATV is carried out with the assistance of Ansys and MATLAB. Heat generated increases the temperature of the disc brake at the rubbing surface resulting in thermal stresses in the components of the braking system. Static, Structural, Thermal, Dynamic, Computational Flow Dynamics, Vibrational & Fatigue Behaviour of Ventilated brake disc Rotor, Hub and Brake Caliper are analysed. Stainless Steel, SS-410 material configuration has been considered for disc brake rotor and results obtained are analysed in terms of performance, longevity and efficiency. Braking efficiency and stopping distance curve are analysed from their characteristics plot. Vibrational Behaviour, Static and Structural Behaviour, Thermal Behaviour, Performance Efficiency, Flow Behaviour of Ventilated Disc Brake Rotor can be easily depicted with respect to Bump and Droop during Acceleration, High Climb and manoeuvrability.
Grey cast iron alloys for brake drum and brake disc applications are being developed with niobium additions and a range of equivalent carbon for commercial, passenger vehicle, and performance applications. The benefit of niobium in cast iron is based on the contribution of strength by matrix refinement for a given carbon equivalence that may permit the direct improvement of wear improvement or allow for an increase in carbon equivalence for a given strength. Proper carbon equivalency and pearlite stabilization contribute to an improved pearlite structure with an optimized distribution of graphite. These structures, when refined with niobium, demonstrate increased service life and reduced wear relative to their niobium-free equivalents as measured by lab dynamometer testing and by on-vehicle testing in passenger bus fleets.
In order to keep the coefficient of friction stable, some additives such as metal sulphides, are included in the brake pads formulation. Previous work from RIMSA has shown that oxidation temperature range of the metal sulphides can be one of the key properties to explain their contribution to the performance and wear of a PAD. This new work is a step forward in the interpretation of the mechanism of sulphides as chemically active additives in the brake pads. Phenolic resin is the matrix of the brake pads and starts to decompose around 300 ºC in presence of oxygen and temperature. In order to establish a connection on between sulphide oxidation and phenolic resin degradation, several studies based on heat treatment of blends of different metal sulphides (Iron sulphide, Tin sulphide and Composite sulphide) with phenolic resin have been done. Then the material evolution was studied with techniques such as TGA - DSC, XRD, IR and SEM - EDS.
Abstract: Attapulgite, a unique clay mineral is a crystalloid hydrous magnesium-aluminium silicate, composed of silicon oxide, aluminium oxide, magnesium oxide, iron oxide etc. having formula Mg5Si8O20(HO)2(OH2)4•4H2O. Its structure is somewhat between laminated and chain structure having very high surface area and porosity. Its magnesium silicate structure resembles a brick wall with every second brick missing. This leaves elongated porous channels that are highly absorbent. Its fibers were proven to be excellent substitute for asbestos in brake-pads. Hardly anything in details is reported on its exact role in controlling tribo-properties of friction materials (FMs) especially Cu-free FMs. Hence, in this work a series of brake-pads with five types was formulated and developed with increasing amount of attapulgite (0, 5, 10 and 15 wt. %) by compensating with inert barite particles in Cu-free FMs.
Graphite plays a crucial role in friction materials, since it has good thermal conductivity, lubricity and act as a friction modifier. The right type, amount, shape, and size of the particles control the performance of the brake-pads. The theme of the study was investigating the influence of size of graphite particles (having all other specifications identical) on performance properties of brake-pads containing graphite particles in the average size of 60 µm, 120 µm, 200 µm and 400 µm. Physical, mechanical and chemical characterization of the developed brake-pads was done. The tribological performance was studied using a full- scale inertia brake dynamometer following a Japanese automobile testing standard (JASO C406). Tribo-performance in terms of fade resistance, friction stability and wear resistance were observed best for smaller graphite particles. It was concluded that smaller size serves best for achieving best performance properties barring compressibility.
The oxidation of raw materials, such as phenolic resin, in the pad during the braking depends on the temperature but also on the oxygen diffusion capability through the brake pad. Determination of oxygen diffusion is a key point in knowing how deep from the surface tribochemistry can take place. In previous work from RIMSA, it was observed that iron sulphide had been reacted below the surface of the brake pad, suggesting that tribochemistry does not only take place on the surface. The diffusion of oxygen through the pad is a drawback because it induces the matrix decomposition that contributes to intra-stop CoF instability and consequently worsens NVH. This study is focused on determining the oxygen diffusion through brake pads using oxidized iron sulphide particles as indicator parameter. Iron sulphide has a peculiar microstructure (rough microstructure) when it becomes oxide that can be recognized easily, making it a good marker.
Gray cast iron brake rotor experiences substantial wear during the braking and contributes largely to the wear debris emissions. Surface coating on the gray cast iron rotor represents a trending approach dealing with the problems. In this research, a new plasma electrolytic aluminating (PEA) process was used for preparing an alumina-based ceramic coating with metallurgical bonding to the gray cast iron. Three different types of brake pads (ceramic, semi-metallic and non asbestos organic (NAO)) were used for tribotests. Performances of PEA coatings vs. different brake pad materials were comparatively investigated with respect to their coefficients of friction (COFs) and wear. The PEA-coated brake rotor has a dimple-like surface which promotes the formation of a thin transferred film to protect the rotor from wear. The transferred film materials come from the wear debris of the pads. The secondary plateaus are regenerated on the brake pads through compacting wear debris of the pads.
In the last decade, the increasing electrification of road transports has stimulated the look for new braking systems with a high corrosion resistance. This resulted in a fervent research activity behind the development of disc brakes with a reduced corrodibility under demanding tribocorrosive environments. Despite of this, a significant reduction of the cast iron disc corrodibility can be achieved not only by developing variously coated rotors, but also by modulating the intrinsic corrodibility of iron. This can be done by and ad-hoc refining of the cast iron: a) alloying elements concentration; b) microstructure; and c) carbon content and morphology. At this regard, in this contribution, the corrosion properties of a representative ensemble of cast iron specimens are reviewed.
As of today, the corrosion resistance of a braking system is considered as important as the braking performance. This is particularly true when considering the emergent electrification of road transports which requires braking systems with a service life as long as the whole vehicle life . Following this, among brake system manufacturers, the research for corrosion protection strategies is driving the development of new discs and calipers aiming at improving their performance during corrosion (e.g. Neutral Salt Spray Tests) and/or tribo-corrosion tests (e.g. bench testing in corrosive environments). It has been demonstrated  that depending on: a) the design of the brake caliper; b) the chosen materials; and c) the adopted protection strategies (painting, anodization, etc.), several galvanic couplings are present within a braking system and could lead to severe corrosive phenomena including pitting and surface diffuse corrosion.
Brake calipers for high-end cars are typically realized using Aluminum alloys, with Silicon being the most common alloying element. Despite the excellent castability and machinability of AlSix alloys, anodization is often necessary in order to provide to AlSix components the required corrosion resistance or when the braking system has to withstand to severe chloride-rich environments . Even if the anodization process is known for almost 100 years, a continuous research and process optimization can lead to the development of anodic layers with enhanced morphological and electrochemical properties, which enable a prolonged resistance of calipers under endurance corrosive tests (e.g. >1000hours Neutral Spray Tests).
The development and production of resonators on the charged air side of combustion engines require profound base of knowledge in designing, simulating and the production of such parts in different materials (aluminum, copper, stainless steel and technical plastic). As combustion engines are under constant discussion, this existing knowledge base should be used for other applications within and outside the automotive industry. Very quickly it became apparent that new challenges often require completely new solutions, designs and materials to meet the requirements of flow noise reducing parts. For example, for clean air applications mufflers based on “special treated foams” and “meta-materials” can be introduced. These materials offer new potentials for tuning of the frequency range and allow improved broad banded flow noise attenuation. Such parts are named “Resabtors” in order to take respect of the different flow noise attenuation principles resonation and absorbing.
This SAE Recommended Practice describes an empirical method for determining the theoretical ash content of aviation piston engine lubricating oils by calculating the equivalent weight of metallic oxides formed at 775 °C based on the metallic elemental concentration. The calculation method of ash determination may be used as an alternate to ASTM D 482 for application to the standards for aviation piston engine lubricating oils.