Search Results

Flexibility, oil resistance, and the need for heat resistance to 150°C-plus temperatures have traditionally limited automotive design engineers to two options - thermoset rubber or heat-shielding conventional thermoplastic elastomers (TPE). Both of these options present limitations in part design, the ability to consolidate the number of components in a part of assembly, and on total cost. This paper presents a class of high-performance, flexible thermoplastic elastomers based on dynamically vulcanized polyacrylate (ACM) elastomer dispersed in a continuous matrix of polyamide (PA) thermoplastic. These materials are capable of sustained heat resistance to 150°C and short-term heat resistance to 175°C, without requiring heat shielding. Recent advancements in blow molding and functional testing of the PA//ACM TPEs for automotive air management (ducts) and underhood sealing applications will be shown.

As part of the 1997 Propane Vehicle Challenge, a team of twelve UTEP students converted a 1996 Dodge Grand Caravan with a 3.3 L V6 engine to dedicated Liquefied Petroleum Gas (LPG) operation according to the 1997 Propane Vehicle Challenge (PVC) competition rules (16). The 1997 UTEP team developed an LPG liquid phase port fuel injection (LPP-FI) system for the minivan. The UTEP design strategy combines simplicity and sound engineering practices with the effective use of heat resistant materials to maintain the LPG in the liquid phase at temperatures encountered in the fuel delivery system. The team identified two options for fuel storage with in-tank fuel pumps. The competition vehicle incorporates a five-manifold eight inch diameter Sleegers Engineering LPG tank fitted with a Walbro LPTS in-tank pump system, providing a calculated range of 310 city miles and 438 highway miles.

Challenges surrounding OEM′s go far beyond to manufacture and delivery high quality vehicles. A perfect design and performance in the lowest cost possible is extremely essential to delivery to the customer the best vehicles. In order to guarantee all these targets, a robust process must be set to developed and implemented. It is known all process limitations, which faces the emergent markets and the lack of infrastructure considering the developed countries. All this limitations can deeply affect the robustness of the process. Some innovative solutions are becoming common from the engineering development combined with the manufacturing team to work out these limitations and provide excellent process stability. In this present paper it will be discussed the Bi component structural adhesive (2K PU epoxy) utilization to establish the process in the assembly line, mainly in order to improve parts dimensionally.

Engines are assigned big subjects such as low emission and low fuel consumption as well as higher output (higher efficiency) in the latest trend of environmental protection. In order to meet these requirements, Air/Fuel ratio of recent high performance engines is being arranged leaner than that of conventional engines. As a result exhaust valve seat inserts used in these engines have problems of their wear resistance because of high exhaust gas temperature. By analyzing wear mechanism under the lean burn conditions, authors developed material for exhaust valve seat inserts which show superior wear resistance under high operating temperature. For the purpose to enhance heat resistance, authors added alloy steel powder for matrix powder and used hard particles which have good diffusion with matrix. The developed material does not include Ni and Co powders for cost saving and has superior machinability.

A catalyzed hydrocarbon (HC) trap aiming at the super-ultra low emission vehicle (SULEV) regulation was developed using a metal-impregnated zeolite. To enhance the adsorption and to raise the desorption temperature for a wide range of HC species, the modification of zeolite with certain metals was needed and Ag was found to be the most promising. Using a Ag impregnated zeolite, a three way catalyst was prepared, and its HC purification ability for a model gas simulating cold-start HCs was studied. Its heat resistance was also examined. A vehicle test for a fresh catalyzed HC trap showed that the cold-start HC after the newly developed trap almost reached the SULEV regulation level.

Automotive friction materials are composites containing three kinds of components: an organic binder, fiber for reinforcement, and property modifiers. At low braking temperatures, the wear rate of the friction materials is controlled primarily by abrasive and adhesive mechanisms. At higher braking temperatures, the wear rate increases exponentially with increasing temperature due to thermal degradation of the binder and other components, and the exponential wear rate is frequently accompanied by brake fade. Thus, one method of reducing thermal wear and fade tendency is to lower the temperature at the rotor/friction material interface. Since the rate of heat transfer from the interface is mostly dependent upon the conductive and convective modes, a rotor of high thermal conductivity will have a significant advantage over a rotor of low conductivity, if the heat capacity remains the same.

Nickel-5 Aluminum (95 % Nickel-5 % Aluminum) is widely used in the aircraft engine industry. The excellent adhesive and cohesive strength of the coating, oxidation resistance and machinability make it an ideal material as both a bond coat for subsequent topcoats and as a build up material for dimensional restoration of worn or mismachined components. Plasma spraying has traditionally been the thermal spray process used to apply nickel aluminum, and the technical properties and performance characteristics are well documented. More recently, wire arc sprayed nickel aluminum is becoming widely used as an alternative to plasma spraying due to higher bond strengths, reproducibility, better machinability and more favorable economics. This paper presents the results of a testing program designed to compare the technical properties of arc sprayed versus plasma sprayed Nickel-5 Aluminum coatings.

The vast majority of products contain joints, therefore, joining technology is key to the strategic implementation of new materials. This paper considers three innovative solutions to industrial problems ClearWeld™ A recently developed technique for laser welding materials, creating a joint almost invisible to the human eye. AdhFAST™ This novel, three-in-one fastener, allows adhesive to be injected through the middle of the device whilst retaining the joint and controlling bondline thickness Vitresyn™ Transparent plastics such as polycarbonate and acrylic have the potential to replace glass in a number of applications, car headlamps and spectacle lenses for example. However, these plastics are relatively soft materials and need protection against abrasion and scuff damage. This recently developed system gives good protection at acceptable cost

Ice adhesion characterization relies heavily on experimental data, especially when dealing with fracture parameters. In this paper, a complementary framework encompassing experimental testing with the numerical treatment of the fracture variables is proposed to provide a physical description of adhesive fracture propagation at the interface of an iced structure. The tests are based on a quasi-static flexural testing setup composed of a displacement-driven actuator and an iced plate. The measured crack length and plate deflection provide the data to be analyzed by the Virtual Crack Closure Technique in order to approximate the critical energy release rate required to study adhesive fracture propagation. The critical energy release rate in mode II is under-predicted and its value is approximated using its counterpart in mode I.

Urethane is utilized to bond the windshield and backlite to the vehicle frame. The contribution of different modulii of glass bonding urethane adhesives on the stiffness characteristics of the vehicle is studied through finite element analysis. The modal analyses of a finite element body-in-white model with different modulii of urethanes are performed, and the analyses show that high modulus urethane makes notable contribution to the vehicle stiffness. The optimized modulus of urethane adhesive is suggested based on the analyses.

Effective use of adhesive bonding in automotive vehicle bodies requires analytical methods for durability, so that potential fatigue problems and unnecessary overdesign may be eliminated before the physical prototype stage and release of product with unquantified safety factors avoided. This paper describes a fracture mechanics-based method for predicting the durability of adhesive joints, based on work previously carried out at Volvo [1]. The method requires relatively modest modifications to a typical vehicle body FE mesh. Adhesive bonds are represented by bar elements around the periphery of each bond. Grid point forces from shell elements adjacent to the adhesive bond are recovered and used to determine line forces and moments at the edge of the glued flange. These forces and moments are then transferred to an analytical sandwich model of the joint.

A new heat resistant aluminized steel, trade named ALUMA-TI, has been developed which has unique mechanical and corrosion properties especially attractive for high temperature applications where economy is a prime consideration for material selection. Presented are its mechanical properties and response to various corrosive environments. High temperature strength and oxidation resistance is far superior to Type I ALUMINIZED steel at temperatures above 704°C (1300°F). In combined oxidation/corrosion tests, ALUMA-TI is comparable to AISI 409 stainless steel. Therefore, ALUMA-TI is a prime material candidate for automotive exhaust systems.

Adhesive bonding technology is playing an increasingly important role in automotive industry. Ultrasonic evaluation of adhesive joints of metal sheets is a challenging problem in Non-Destructive Testing due to the large acoustic impedance mismatch between metal and adhesive, variability in the thickness of metal and adhesive layers, as well as variability in joint geometry. In this paper, we present the results from a matrix array of small flat ultrasonic transducers for evaluation of adhesively bonded joints in both laboratory and production environments. The reverberating waveforms recorded by the array elements are processed to obtain an informative parameter, whose two-dimensional distribution can be presented as a C-scan. Energy of the reflected waveform, normalized with respect to the energy obtained from an area with no adhesive, is a robust parameter for discriminating "adhesive/no-adhesive" regions.

We have developed a new alumina multi-layer ceramic substrate material, whose properties of low resistance conductor and excellent mechanical and thermal characteristics, providing a new and unique substrate solution for automotive ECU applications. Unique to this material is the circuit conductor which is made from a composite material of tungsten and copper, providing low electric resistance and high thermal diffusivity. This material system (AO600) utilizes a low-temperature, co-fireable alumina with a low resistance metal conductor composite. Electric current path is made by copper in the composite to effectively reduce the resistance. Thick film on the alumina substrates surface is also effective for the resistance reduction. Using this material system, substrates with miniaturized design, high strength and high thermal diffusivity have been realized. We have also tested reliability by temperature cycle tests between -40 and 150 degrees centigrade.

The front-end carrier (FEC) refers to the part of a car, which supports most of the cooling package, headlights, latch and various other components. It also ties the upper and lower longitudinal rails and plays a role in the structural stiffness of the car. Traditional front-ends carriers are built up from steel and bolted or welded to the body-in- white (BIW). In recent years, however, there has been a trend towards mounting the complete front-end system (FES), as a module, onto a BIW with an open structure. The FEC assembly then connects the longitudinal rails. This allows reductions in cost, moves part of the assembly away from the OEM and often improves the overall quality. The move to modular systems opened the door to the use of plastics. Use of molded plastic carriers allows integration of parts and functions, weight reductions and cost advantages.

The introduction of marine super-long stroke (SLS) crosshead engines to provide lower operating and maintenance costs has placed a greater stress on the performance requirements of cylinder oils. Key performance parameters affected include: corrosive, adhesive, and abrasive wear and piston deposits. This paper presents the results of laboratory engine tests from cylinder oil formulations containing balanced additive chemistry blended to optimize viscosity using various base stocks and highlights the contributions of the individual additive properties, viscometrics, and combinations to maximize performance. Observations from interim ship-service trials are also included.

A new proportional collection system for extremely low tailpipe emission measurement in transient conditions has been developed. The new system can continuously sample a minute flow of exhaust gas, at a rate that is proportional to the engine exhaust rate. A zero grade gas dilution technique is utilized to prevent the influence of pollutants in atmospheric air that are the same concentration level as those in the exhaust gas. The system has accuracy within ±5%. For the direct exhaust gas flow meter, a pitot tube type flow meter is utilized as it is simple, heat resistant, sufficiently accurate and has low flow-resistance characteristic. For the collection and dilution controllers, two mass flow controllers (MFC) were adopted. The MFCs' output can be adversely influenced by variation of the specific heat of the sample gas, resulting in flow reporting error.

We have made a new rig of the friction and wear testing rig which researches the slipping and adhesive wear characteristics of the automobile elements under vibrating and loading conditions, and also evaluates the effect of lubricating oil on the friction and wear of materials. The dynamic characteristics of the tribology of materials can also be assessed with this testing rig. This tester can automatically and synchronously measure and record the dynamic friction force, the coefficient of friction, and the resulting pressure during the tests. The tester has been equipped with a microcomputer which samples displays and records the test results. The tester is sensitive of good reproducibility, and achieves consistent results.

The development of a puncture sealant which effectively seals tread punctures 3/16 inch diameter and less is described; included are discussions of the material compositions and properties, the mechanism of sealing, and field testing of the product.

Forty billion dollars are lost each year due to the failure of various components in a vast array of electronic devices. These failures result in downtime for part replacement, product liability issues, and critical safety ramifications. Many of the failures are caused by corrosion due to the migration of moisture or solder flux through leak paths inherent in electronic connectors and other parts, typically at the interface between metal leads and plastic housings into which they are molded. All industry standard approaches to preventing these failures have severe limitations and drawbacks. The approaches include discarding parts that fail a leak test, employing elaborate hermetically sealed encasements, or applying surface sealants. Each method of solving the problem creates other problems: costly high scrap rates, heavy, bulky assemblies, or introduction of a foreign material through surface sealants.