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Although P/M part producers have been supplying 410 and 316-base stainless steel parts for almost fifty years, P/M versions of these materials have been excluded from many moderate to severe applications due to their marginal corrosion resistance. There have been a number of efforts targeted at improving P/M stainless corrosion properties but performance comparable to the wrought stainless products has not yet been achieved. The work reported here discusses corrosion and mechanical properties obtained for modified steel alloys which have shown significantly better resistance to corrosion in simulated sea water (5% NaCl solution) while maintaining reasonable physical and mechanical properties.

Evaluation of commercial high temperature H2-sintered 410L ABS sensor rings, after use for over 10 years and/or over 100,000 miles in various automobiles and in various locations across the USA and Canada, showed only small amounts of rusting; less than which results in a 100-hour Salt Spray Test (ASTM B117); and no loss of their mechanical strength and ductility. Although sensor rings made of 434L and 434L-Modified (18 Cr, 2 Mo) show even lesser amounts of rusting and pitting, 410L sensor rings made by the above process are deemed adequate for this application. The 1000-hour Salt Spray Test is found to be much too severe for this application. A 100-hour test is considered to be more suitable in this regard.

High performance auto parts such as aluminum composite cladding aluminum brake and Ti/Ti3/Al joined exhaust valve with localized Ti+TiC composite coating could be produced using a new manufacturing method - the CastCon process. The aluminum composite cladding aluminum brake consists of an aluminum alloy body with a cladding of SiC and graphite particulate filled aluminum composite on the friction surface of a brake disk or a drum. This structure can ensure an over-all light weight and integral strength and ductility. The SiC particulate in the cladding composite increases abrasion resistance and the graphite particulate provides required lubrication. The cladding can be as thick as desired. There is a flexibility in the manufacturing process for selecting SiC and graphite loading volumes as well as particulate size and shape. This allows the part to be engineered to achieve maximum performance.

The performance of stainless steel(SS) powder metallurgy (P/M) materials in elevated temperature applications has become a subject of interest with P/M now being considered for automotive exhaust type applications. This study will outline the results of an investigation into the properties of several P/M stainless steel materials at elevated temperatures and relate these P/M materials to ingot metallurgy counterparts. Recommendations on the manufacturing of stainless steel P/M exhaust system components will also be presented.

Turbine hubs for automatic transmission torque converters are ideal candidates for the powder metallurgy (P/M) process. The complex shape of turbine hubs is costly to produce via conventional forging and machining operations. Increases in engine size and torque requirements by automotive designers require turbine hubs to possess high levels of mechanical properties. High density P/M manufacturing techniques, in combination with high performance ferrous material produces components capable of replacing a forged and machined turbine hub. This paper will review the conversion of a conventionally forged and machined turbine hub used in a high torque automatic transmission to a single pressed and single sintered P/M turbine hub. The material used for the P/M hub was an MPIF FD-0405. Warm compaction processing achieved significantly increased overall sintered densities in the highly stressed internal spline region.

Today, light connecting rods are vital to satisfying the demands of modern internal combustion engines. HYUNDAI Motor Company (HMC) has applied powder metal forged connecting rods instead of conventional hot forged connecting rods to obtain low product costs and to improve NVH characteristics and bearing reliability. Light connecting rods were developed through optimized design with high quality and low cost. Notably, the mass of a powder metal forged connecting rod is 17.7% lighter than that of a conventional hot forged type connecting rod, and its crank end is 22.5 % lighter than that of a conventional type connecting rod. Light connecting rods result in reduced crankshaft mass, so the mass of the main moving parts can be reduced. With this mass reduction, bearing reliability and NVH characteristics can be enhanced.

Increasing demands are being placed by automotive OEM's on valve seat insert suppliers to improve the machinability of their products due to the direct impact on the productivity at the cylinder head machining line. To meet this challenge, a new P/M valve seat insert material was developed through a partnership between OEM, a valve seat insert manufacturer and a powder supplier. The object of this paper is to compare current materials to the new material's enhanced machinability through powder characterization, material properties and machinability studies. The effect of machinability enhancement additives, P/M processing and machining parameters are also reviewed.

The highly dynamic process in a pyrotechnic inflator and in a canister-airbag system was simulated by using two compressible gas thermal energy numerical models. First a 2-D model was used to simulate flow through the inflator porous media; then results from the first model were used as input to a second 2-D model to compute pressure, temperature and flow patterns in the airbag. Results show a complete picture of the dynamics of the airbag inflator - canister system during deployment.

The effects of stress in brain material was investigated with experimental and computational idealizations of the head. A water-filled cylinder impacted by a free traveling mass serves to give insight into what could happen to the brain during impact. Under an impact of sufficient velocity, cavitation can occur on the cylinder boundary opposite impact. Limited internal vaporization of the fluid may also occur during severe impact events. Cavitation occurred in these experiments at accelerations greater than 150 g's. Head forms of different sizing will experience an acceleration magnitude inversely proportional to the size difference to produce a similar pressure/cavitation response.

The William Lehman Injury Research Center has conducted multi-disciplinary investigations of one hundred seventy-eight crashes involving adult occupants protected by safety belts and air bags. In all cases, serious injuries were suspected. Nine cases involved serious heart injuries. These cases are not representative of crashes in general. However, when used in conjunction with National Accident Sampling System; Crashworthiness Data System (NASS/CDS) they provide insight into the most severe injuries suffered by restrained occupants in frontal crashes. Heart injuries are rare, but when they occur they are usually life threatening. NASS/CDS shows that heart injuries comprise about 0.2% of the injuries in frontal tow-away crashes. In the NHTSA file of Special Crash Investigations (SCI) of air bag cases, heart injuries are reported in 1% of the occupants over 15 years of age. Twenty-five percent of the fatally injured occupants had heart injuries, and 83% of those with heart injury died.

This paper provides a methodology for adjustment of off-speed head impact test data to the required 24.14 km/h for interior head impact. The “Normalization Process” utilizes the Generic Waveform Concept for its basic foundation. Predicted results from FE Head Impact Simulation Model were used to validate the Normalization Process. It is recommended that Normalization should be applied to cases where impact velocities are within ±0.8 km/h speed difference. In general, Normalizing down-speed (from 24.94 to 24.14 km/h) is preferred over Normalizing up-speed (23.33 to 24.14 km/h). One must always check for potentially severe “bottom-out” condition by examining the pulse shape for any abrupt peaks in headform deceleration. The Normalization Process should not be applied to “glancing” impacts in which the impact and rebound vectors are not colinear.

Trim covers made of impact resistant polymers on vehicle interior sheet metal can contribute to reduction of HIC(d) (Head Injury Criterion, dummy) during headform impact. Air-gap between trim and interior sheet metal can also induce deceleration of striking headform before it forces trim to contact sheet metal surface. As evidenced from laboratory component testing, situations may arise where additional protective measures may need to be incorporated between trim and sheet metal in order to attain acceptable levels of HIC(d). Two such alternatives in the form of energy-absorbing foam, and trim with molded collapsible stiffeners are discussed in this paper. The effectiveness of these countermeasures is evaluated through nonlinear finite element analysis, and favorable comparison with laboratory results is reported.

This work addresses and evaluates the likelihood of human casualty in highway crashes, projected on the basis of field crash data that may become available electronically by sensors at crash time, and/or observed at the crash scene by emergency attendants. Termed collectively as a “crash signature”, such data are treated as predictors and are selected from: crash severity, general area of damage, direction of force, occurrence of rollover, intrusion, vehicle crush and its specific horizontal location, collision partner, vehicle class and size, occupant age, gender, restraint use and type, seating position, and other. Crash signatures are converted into responses such as: (a) the likelihood of the most severe outcome, fatality or survived injury, by severity AIS per occupant; and (b) the same per vehicle. Cars are the vehicles selected for this investigation.

The first single-piece, rear bumper system injection molded from an engineering thermoplastic provides 8 km/h pole impact as well as required Federal Motor Vehicle Safety Standard (FMVSS) protection requirements for a small passenger vehicle. The system's efficient design features integral fascia support, eliminating bracketry and providing assembly savings at the plant. The bumper offers a 1.5 kg mass savings compared to conventional aluminum and polypropylene foam bumper systems. Additionally, its low intrusion design means neither the rear end panel nor the deck lid was damaged at the 8 km/h impacts tested. This paper will describe the bumper's design, development, and validation process, plus describe the results achieved to date.

Developed specifically for the automotive industry, a new glass-mat thermoplastic (GMT) composite technology provides significant improvements in strength and energy management behavior for automotive bumper applications. This increased performance is achieved through the use of new fiberglass mat design, sizing chemistry, and binder resin technology vs. standard GMT composite products with the same type and percentage of glass loading. No substantial tooling and processing changes are required to make use of the new products, which are interchangeable in current GMT molds. In order to fully evaluate the new materials, actual direct-mountable automotive bumper beams were molded and tested in both static and dynamic modes. The results of this testing demonstrate the new composites' ability to achieve Federal Motor Vehicle Safety Standard (FMVSS) 581 8 km/h impact performance without the need for costly hydraulic or foam energy absorption (EA) units.

The commercial validation of a optimized RRIM polyurethane substrate with a novel barrier coat for fascia applications is reviewed which creates cost competitiveness to thermoplastic olefins (TPO), without sacrificing performance. Meeting fascia performance requirements with thinner and lighter RRIM materials containing recyclate and the subsequent application of a barrier coat eliminating the traditional primecoat cycle was investigated.

Microfibers with high specific micro-surface can be knitted into two-dimensional structures with large internal porosity. Catalytically active metals can be deposited on the fibers with high dispersion by wet-impregnation, sol-gel or CVD, respectively. These microfiber knits may be used for exhaust gas treatment systems with a triple function: particle filtration, gas conversion and muffling. The total oxidation of propane on Pd and Pt coated fibers has been studied as a test reaction. Conversion temperature could be remarkably reduced compared to cellular structures. For a bimetallic (Pt-Pd) coating, the activity is independent of humidity or oxygen concentration. Thus a catalytic converter based on micro-fiber knits appears feasible. Its high mass and heat transfer prevent hot spots. And it functions as submicron filter for combustion aerosols. Integrated electric heating can also be provided in case of low gas temperatures. First tests on engines show promising results.

Diesel engines are irreplaceable in tunnel construction. The particulate emissions of present day engines are so high that the imission limits valid since 1991 cannot be attained by ventilation alone. This problem had to be solved preparatory to the large tunnel projects in Switzerland, Austria and Germany. Several retro-fitting measures were investigated both in the laboratory and in field tests, within the scope of the Project VERT. Oxidation catalytic converters, exhaust gas recirculation, and the usage of special fuels cannot be recommended. Particulate trap deployment, in different systems, was mostly successful. Particular attention was focused on the dependable filtration of finest particulates < 200 nm. The VERT proved that exhaust gas after-treatment with particulate traps is feasible, cost effective and controllable in the field. Pertinent directives are in discussion.

New developments for optimized control of Aerodynamically Regenerated Traps (ART) - Exhaust Gas Recirculation (EGR) integrated systems for diesel engines are presented herein. Such systems employ high-efficiency ceramic monolith filters to retain 99% of the emitted particulates. Regeneration is achieved periodically by short pulses of compressed air, flowing in the opposite direction to the exhaust. The soot is collected in a chamber, outside of the monolith, where it is oxidized with an electric burner. A fraction of the filtered exhaust is returned to the engine and this reduces NOx emissions, typically, by more than 50% at 18% EGR. However, since the amount of EGR, the frequency of regeneration and the frequency and duration of burning have a bearing on the fuel consumption of the engine, their optimization is imperative. Thus, provisions were made to collect intelligent information, leading to continuous assessment of the engine performance and fuel economy.

A particulate aggregate model which takes place during the incomplete combustion of Diesel1 fuel in heavy duty engines is presented. An approximate analytical solution for the temperature field in a filter ceramic porous wall is presented. An alternative approach covering essential engineering problems is presented by means of a numerical simulation, which shows safety operational features of the proposed scheme. Some predicted performance of the filter ceramic traps are also presented.