scholarly journals Strength and fatigue of NT551 silicon nitride and NT551 diesel exhaust valves

2000 ◽  
Author(s):  
M.J. Andrews ◽  
A.A. Werezczak ◽  
T.P. Kirkland ◽  
K. Breder
Keyword(s):  
Silicon Nitride ◽  
Diesel Exhaust ◽  
Exhaust Valves

scholarly journals Strength and Fatigue of NT551 Silicon Nitride and NT551 Diesel Exhaust Valves

2000 ◽  
Author(s):  
M.J. Andrews ◽  
A.A. Wereszczak ◽  
T.P. Kirkland ◽  
K. Breder
Keyword(s):  
Silicon Nitride ◽  
Diesel Exhaust ◽  
Exhaust Valves

A Fundamental Study on the Prediction of Preheating Temperature of Silicon Nitride Ceramics by Using HPDL

2012 ◽  
Vol 229-231 ◽  
pp. 287-291 ◽  
Author(s):  
Kwang Sun Kim ◽  
Choon Man Lee
Keyword(s):  
Thermal Analysis ◽  
Silicon Nitride ◽  
Ceramic Materials ◽  
High Temperature Strength ◽  
Heat Sources ◽  
Fundamental Study ◽  
Silicon Nitride Ceramic ◽  
Preheating Temperature ◽  
Nitride Ceramics ◽  
Exhaust Valves

Silicon nitride ceramic has been used in various engineering applications such as bearings, rollers, and exhaust valves for automobiles because of its corrosion resistance, high-temperature strength and low density. LAM (Laser assisted machining) has recently been considered as an alternative and effective process for machining ceramic materials. The laser heat sources in laser assisted milling processes are irregularly varied according to shapes of workpieces. Therefore, prediction and analysis of preheating temperature is difficult. In this study, the thermal analysis and experiment were performed to evaluate the surface temperature distribution of silicon nitride according to laser power. In addition, the preheating temperature was predicted by analyzing the results of the thermal analysis.

NICROFER 7016TiAl

Alloy Digest ◽  
2006 ◽  
Vol 55 (2) ◽  
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Diesel Exhaust ◽  
Rupture Strength ◽  
Slight Modification ◽  
Heat Treating ◽  
Age Hardening ◽  
Good Corrosion Resistance ◽  
Temperature Performance ◽  
Exhaust Valves

Abstract Nicrofer 7016TiAl (also known as alloy 751) is an age-hardening Ni-Cr-Fe alloy with both good corrosion resistance and high rupture strength. It is a slight modification of alloy Nicrofer 7016TiNb (alloy X-750) and is used in diesel exhaust valves. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as creep. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Ni-630. Producer or source: VDM Technologies Corporation.

Development of Advanced Silicon Nitride Valves for Combustion Engines and Some Practical Experience on the Road

1992 ◽  
Vol 287 ◽  
Author(s):  
Rainer Hamminger ◽  
Juergen Heinrich
Keyword(s):  
Silicon Nitride ◽  
Internal Combustion Engines ◽  
Bending Strength ◽  
Processing Parameters ◽  
Practical Experience ◽  
Combustion Engines ◽  
The Road ◽  
On The Road ◽  
Exhaust Valves ◽  
Fuel Consumption And Emissions

ABSTRACTOne major goal of automotive engineers actually is to reduce fuel consumption and emissions of present internal combustion engines. First promissing results have been achieved by the substitution of conventional by silicon nitride valves. The weight reduction of about 60 % per valve is corresponding with lower inertia and spring forces, which lead to improved emissions, reduced fuel consumptions as well as high performances of the engines. Applying statistical methods, two advanced silicon nitride materials have been developed, concerning their application as “cool” inlet valves and “hot” exhaust valves, respectively. Using high quality powders and combined optimum processing parameters, 4-point-bending strength of more than 1200 MPa (room temperature) and 870 MPa (1000 °C), resp., have been realized. Weibull moduli of more than 30 have been reproduced. Grinding of valves produced from these materials has economically been demonstrated by drastically reducing the machining times. Some results of road tests as well as of simulated engine tests from cooperations with different automotive companies are presented in detail.

Diesel Exhaust Valves

1966 ◽  
Author(s):  
Vernon A. Johnson ◽  
Clifford W. Galen
Keyword(s):  
Diesel Exhaust ◽  
Exhaust Valves

scholarly journals Corrosion resistance of valve steel in diesel exhaust gas containing 5, 10 and 20 % of FAME

2013 ◽  
Vol 152 (1) ◽  
pp. 51-55
Author(s):  
Andrzej SUCHECKI ◽  
Krzysztof ADAMASZEK ◽  
Mariusz WISŁA
Keyword(s):  
Corrosion Resistance ◽  
Diesel Exhaust ◽  
Diffusion Processes ◽  
Oxidation Catalyst ◽  
Exhaust Gas ◽  
Durability Test ◽  
Term Operation ◽  
Mechanical Tensions ◽  
Valve Steel ◽  
Exhaust Valves

The operating properties of exhaust valves under heavy thermal and mechanical loads are dependent on the strength of steel i.e. resistance to mechanical deformations under increased and high temperatures and high temperature corrosive action of hot exhaust gas. Long term operation of exhaust valves under the conditions of cyclic thermal and mechanical tensions in the environment of diesel exhaust gas where the main oxidizing components are oxygen, carbon dioxide and overheated steam leads to a corrosion of the steel surface and diffusion processes on the thin surface layer of steel, which, under extreme conditions, may lead to a deformation of the valve, an increased leakage of the combustion chamber and a damage or destruction of the engine. The investigations of the corrosion resistance of valve steel in diesel exhaust gas containing 5, 10 and 20 % of FAME were conducted on the durability test stand of BOSMAL Automotive Research and Development Institute in Bielsko-Biała in the oxidation catalyst chamber under the conditions simulating the operation of exhaust valves in diesel engines. The tests have confirmed that the corrosion resistance of valve steel in diesel exhaust gas decreases with an increased content of FAME in the fuel and as the content of Cr, Si, Ni is reduced in the tested valve steel and the content of Mn is increased in the tested valve steel.

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