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Technical Paper

Wear Evaluation of Niobium-Added Cast Iron for Brake Disc and Drum Applications

2020-10-05
2020-01-1627
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.
Technical Paper

Rust is not a Must. Improvement of Discs Corrosion Resistance by Tuning of Cast Iron Alloying Elements and Microstructure.

2020-10-05
2020-01-1624
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.
Technical Paper

Determination of Diffusion Capability of Oxygen Through Brake Pads From the Surface Towards the Interior

2020-10-05
2020-01-1616
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.
Technical Paper

Wear Performances of Gray Cast Iron Brake Rotor with Plasma Electrolytic Aluminating Coating against Different Pads

2020-10-05
2020-01-1623
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.
Technical Paper

A Study of the Interactions Between Phenolic Resin and Metal Sulphides and their Contribution to PAD Performance and Wear

2020-10-05
2020-01-1600
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.
Technical Paper

Design and Simulation of Braking System for ATV

2020-10-05
2020-01-1611
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.
Technical Paper

Resabtors - Advanced Multi-Material Muffler Designs for Clean Air Applications

2020-09-30
2020-01-1554
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.
Technical Paper

Free Vibrational Characteristics of Dual Side Nd: YAG Laser Welded Stainless Steel 304 joints Reinforced with Al2O3 Micro Powder Particles

2020-09-25
2020-28-0393
Nd: YAG Laser Welding Process (LWP) is the most efficient method commonly used for the joining of different kinds of materials, whether it can be a sheet or plate.LWP in general,uses high power density, frequency and travel speed or feed rate as primary process parameters in order to perform a joining process across the metals. This paper investigates the effect on free vibrational characteristics for Stainless Steel 304 (SS 304) joints which are reinforced with Al2O3 micro particles processed by dual side (welding performed on the top and bottom surface of sheets) Nd: YAG LWP. The inclusion of micro particles was inserted directly across the weld pool region, by fabricating drills with a constant gap between each drilled holes. Totally 12 samples were fabricated with different laser power, travel speed and by keeping the frequency level as constant for all the experiments.
Technical Paper

Experimental Study on Influence of Iron Oxide Nano particles on Characteristics of a Low Heat Rejection Diesel Engine Operated with Methyl Esters of Waste Cooking Oil

2020-09-25
2020-28-0412
In this study, an attempt was made to investigate the influence of Iron Oxide Nano particle on the performance, emission and combustion characteristics of Low Heat Rejection (LHR) diesel engine operated with methyl esters of Waste Cooking Oil (WCOME). In the first phase of the work, single cylinder, direct injection diesel engine test rig was developed and tested for its baseline readings with diesel at different power output. In the second phase of the work, test engine was operated with WCOME and tested for its characteristics. Test engine was modified to operate in the LHR mode in the third phase of the work. Engine's cylinder head, valves and piston crown were coated with lower thermal conductivity materials namely, 200 microns of Yttrium Stabilized Zirconia & 100 microns of Nickel, Chromium and aluminium alloys. LHR engine was tested with WCOME and tested for its characteristics in the fourth phase.
Technical Paper

Methods to Control Curing Induced Distortion in Hybrid Joining of Dissimilar Metals

2020-09-25
2020-28-0401
In lightweight structures with dissimilar metal designs, structural adhesive joining is a potential joining method. Adhesives help in reducing galvanic corrosion by minimizing physical contact between two dissimilar metals. Along with adhesives, fasteners are often used as a secondary joining method to hold the assembly together during adhesive curing. Therefore, a hybrid joint which is a combination of adhesives and mechanical fasteners is potential joining method to join dissimilar metals. However, when two dissimilar metals such as aluminum to steel are joined with hybrid joint by adhesive curing at elevated temperature, the distortion of assembly is observed when cooled at room temperature. This is due to the mismatch between coefficients of thermal expansion of aluminum vs steel. The adhesive may also experience residual stress and fracture. In this study, adhesive curing induced distortion is studied using 1.1 meter long specimens of aluminum to steel hybrid joint assembly.
Technical Paper

Comparative Studies on Conventional groove SMA and GMA welds of Dissimilar 304LN ASS and HSLA Steels.

2020-09-25
2020-28-0405
Dissimilar metal welds (DMWs), between austenitic stainless steel (ASS) and micro-alloyed high strength low alloy steel (HSLA), are used in high temperature applications in power stations and petrochemical plants. The gas metal arc welding (GMAW) has surpassed the shielded metal arc welding (SMAW) process due to its advantages of producing fast, long, clean continuous weld at any position [1-4]. A studies on mechanical and metallurgical properties of conventional V-groove SMAW and GMA Welding of dissimilar 20 mm thick 304LN ASS and micro alloyed HSLA steel plate were carried out by using austenitic E308L- 15 electrode with gas tungsten arc welding (GTAW) root pass. The tensile (axial and all-weld) properties, hardness and microstructure of the weld and HAZ are analyzed.
Technical Paper

Nd: YAG Laser Welding of Stainless Steel 304: The effects of Al2O3 micro particles addition

2020-09-25
2020-28-0418
In the present work, fabrication of similar Stainless Steel (SS) 304 joints by Nd-YAG Laser Welding Process (LWP). A novel approach was attempted in this study, welding was performed on dual sides of the plate (top and bottom) for a better mixture of micro powder particles in the weld pool region and to achieve maximum depth of penetration, which is not easily possible in a single-sided (LWP). High depth of penetration during fabrication of joints, significantly improved the mixture ratio of molten steel with reinforced micro powder particles. Al2O3 micro powder particles were reinforced in the weld pool region through the drilling process with varying depth ratios, and a moderate gap was maintained between each hole. The effects of Al2O3 on the microstructure and mechanical properties were studied and elaborated in brief. Totally 12 samples were fabricated, here joining was performed by keeping the frequency as constant and varying laser power, travel speed for all the trials.
Technical Paper

Experimental studies on weldability of Oil Hardening Non Shrinking die steel

2020-09-25
2020-28-0424
The Oil Hardening Non Shrinking (OHNS) die steel refers to a variety of carbon and alloy steels that are particularly well-suited for making tools. Though these steels are weldable, there is risk of crack formation. But, this can be avoided with convinced specifications like pre heating, proper choice of electrode etc., In the present work, OHNS die steel is welded with three different electrodes. The chosen electrodes are mild steel electrode, E312-16 chromium based electrode and E-NiCrFe-3 nickel based electrode. The OHNS steel is welded with these three electrodes and the welded specimens were examined for hot cracking tendency and mechanical properties of the joint. The hot cracking tendency was assessed by Houldcroft`s weldability test (Fishbone test). All the three electrodes proved the good results in terms of hot crack resistance and the specimen welded with E312-16 chromium based electrode provides good mechanical properties.
Technical Paper

Effect of Shot Peening Exposure Time on Mechanical Behavior of Al 7075-T6 Alloy

2020-09-25
2020-28-0430
This investigation addresses the effect of exposure time applied through shot peening as one of the severe plastic deformation technique on mechanical behavior of Al 7075-T6 alloy. Shot peening induces hardened layer in the surface region due to work-hardening effect by shot peening. The specimen shot peened for 105 s (SP105) exhibited highest values of tensile strength (591 MPa), yield strength (550 MPa) and surface hardness (265 VHN) as compared with untreated specimen with 568 MPa, 504 MPa and 184 VHN respectively. The increment in tensile properties are due to rapid improvement in the surface work-hardening by virtue of peening treatment with 105 s duration. In contrast, the shot peened alloy exhibited lower percentage elongation and higher surface roughness as compared with untreated one. The surface morphology and roughness studies before and after the treatment analyzed by suitable characterization.
Technical Paper

Development of a Magnesium alloyed Front cover for a Light duty Diesel Engine.

2020-09-25
2020-28-0459
With Continuous increase in demand to reduce weight is forcing Automotive Designers towards finding ways to explore new materials for the Engine components. Currently, Aluminium, Thermoplastics and Composites are widely used in Engine application. This papers examines the potential of a Magnesium alloy Front Cover designed to replace the Cast iron Front Cover in a Light duty Diesel engine. In presented study, a Cast iron Engine front cover is re-designed for Magnesium alloy and components developed. Further Magnesium alloy component tested at vehicle level and it has been demonstrated that a magnesium alloy Front cover can achieve key functional requirements such as Structural durability, Sealing, NVH, while providing substantial Weight saving.
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