scholarly journals High Performance Valve Seat Materials for CNG Powered Combustion Engines

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4860
Author(s):  
Andrzej Romański ◽  
Elżbieta Cygan-Bączek
Keyword(s):  
High Speed ◽  
High Performance ◽  
Base Material ◽  
High Speed Steel ◽  
Wear Test ◽  
Gas Temperature ◽  
Valve Seat ◽  
Test Procedures ◽  
Gasoline Engines ◽  
Engine Valves

The conventional copper infiltrated high speed steel (HSS) valve seats used in gasoline engines are not suitable for CNG combustion because the exhaust gas temperature is at least 80 °C higher, which drastically shortens the service life of the engine valves. Therefore, a proprietary high-alloy HSS-base material was designed to combat hot corrosion and mechanical wear of valve seat faces in CNG fuelled engines. A batch of −100 mesh water atomized HSS powder was commissioned. The powder was vacuum annealed in order to reduce oxygen content and increase its compressibility. To improve the final part machinability, 1.2% MnS was admixed to the HSS powder prior to compaction. The green compacts were sintered at 1135 °C in nitrogen to around 83% TD and subsequently infiltrated with a copper alloy. After installing the valve seat components on a cylinder head, the engine was tested for 100 h according to the automotive industry valve seat wear test procedures. Both the periodic 8-h checks as well as the final examination of the valve seats showed very slow wear, indicating their suitability for CNG powered engines.

The Development of a High Speed Steel Based Sintered Material for High Performance Exhaust Valve Seat Inserts

1998 ◽  
Author(s):  
Hideaki Kawata ◽  
Koichiro Hayashi ◽  
Kei Ishii ◽  
Kunio Maki ◽  
Atsushi Ehira ◽  
...  
Keyword(s):  
High Speed ◽  
High Performance ◽  
Sintered Material ◽  
High Speed Steel ◽  
Exhaust Valve ◽  
Valve Seat ◽  
Valve Seat Inserts

Investigation on Wear Behavior at High Temperature of Smooth and Bionic Non-Smooth Samples

2012 ◽  
Vol 157-158 ◽  
pp. 1628-1631
Author(s):  
Xiao Dong Yang ◽  
Zhuo Juan Yang ◽  
You Quan Chen
Keyword(s):  
High Temperature ◽  
Wear Mechanism ◽  
High Speed ◽  
Room Temperature ◽  
Wear Behavior ◽  
High Speed Steel ◽  
Wear Test ◽  
Test Method ◽  
Wear Characteristics ◽  
Pin On Disk

By using pin-on-disk wear test method, the wear behavior of W9Gr4V high speed steel with smooth and non-smooth concave samples which treated by laser texturing technology was investigated between room temperature and 500 . It was found that the anti-wear ability of the non-smooth concave samples was increased more than that of the smooth ones and the anti-wear ability of the non-smooth samples was evident than the smooth ones at temperature increasing. In this paper, the anti-wear mechanism of non-smooth concave samples and wear characteristics with smooth and non-smooth samples in high-temperature were analyzed.

scholarly journals Direct fabrication of high-performance high speed steel products enhanced by LaB 6

2016 ◽  
Vol 112 ◽  
pp. 469-478 ◽  
Author(s):  
Zhang Qiankun ◽  
Jiang Yao ◽  
Shen Weijun ◽  
Zhang Huibin ◽  
He Yuehui ◽  
...  
Keyword(s):  
High Speed ◽  
High Performance ◽  
High Speed Steel ◽  
Direct Fabrication

Influence of Tin Coating on Wear of High Speed Steel Tools as Studied by New Laboratory Wear Test

1989 ◽  
Vol 5 (2) ◽  
pp. 141-150 ◽  
Author(s):  
P. Hedenqvist ◽  
M. Olsson ◽  
S. Söderberg
Keyword(s):  
High Speed ◽  
High Speed Steel ◽  
Wear Test ◽  
Tin Coating

scholarly journals Defect formation and microstructural changes in friction stir welds between pure copper and a brass alloy

2009 ◽  
Vol 15 (S3) ◽  
pp. 79-80 ◽  
Author(s):  
Rui M. Leal ◽  
Carlos Leitão ◽  
Altino Loureiro ◽  
Dulce M. Rodrigues
Keyword(s):  
High Speed ◽  
Defect Formation ◽  
Position Control ◽  
Pure Copper ◽  
Base Material ◽  
High Speed Steel ◽  
Tool Geometry ◽  
Slight Reduction ◽  
Friction Stir ◽  
Brass Alloys

AbstractSeveral attempts have been made in the last few years for joining similar pure copper and brass alloys using the solid state friction stir welding (FSW) process. For both material types, all the works performed reported that the production of defect free welds is largely dependent on the correct choice of process parameters. It was also observed that, despite grain refinement occurred in the centre of all the welds, the welds in copper showed a slight reduction in strength, when compared to that of the base material, as opposed to welds in brass alloys, for which an increase in strength was observed. Regardless of the encouraging results obtained in similar FWS of these materials, in the knowledge of the authors, few reports exist concerning dissimilar joints between them. In his work, dissimilar welds between Cu DHP cooper plates and Cu-Zn 37 brass plates, both of 1 mm thickness, with the brass plate positioned in the advancing side of the tool, were analysed. Welds were carried out with a solid tool made of high speed steel. Tool geometry was characterized by a tool shoulder of 10 mm in diameter, containing a conical cavity of 6 degrees, and a threaded probe of 3 mm in diameter. Welds were done in a milling machine, in position control, using the working parameters indicated in table 1.

scholarly journals Effect of Pulsed Laser Ablation on the Increase of Adhesion of CRN Coating-Substrate

2018 ◽  
Vol 26 (43) ◽  
pp. 61-70
Author(s):  
Paulína Zacková ◽  
Lucia Števlíková ◽  
Ľubomír Čaplovič ◽  
Martin Sahul ◽  
Vitali Podgurski
Keyword(s):  
Laser Ablation ◽  
Residual Stresses ◽  
High Speed ◽  
Substrate Surface ◽  
Base Material ◽  
High Speed Steel ◽  
Cobalt Content ◽  
Deposition Process ◽  
Adhesion Behavior ◽  
Surface Laser

Abstract The contribution deals with analysis of the influence of the substrate surface laser ablation before deposition process to improve the adhesion of coating-substrate system. The coatings were applied to the high-speed steel 6-5-2-5 (STN 19 852) and WC-Co cemented carbide with cobalt content of 10 wt%. LAteral Rotating Cathodes (LARC®) process was chosen for evaporation of individual CrN layers. Influence of laser ablation on the substrate morphology, structure, roughness, presence of residual stresses inside the substrates and layers and their adhesion behavior between the layers and the base material was studied. Scanning electron microscopy fitted with energy dispersive spectroscopy was utilized to investigate morphology and fracture areas of substrates with CrN layers. X-ray diffraction analysis was employed to detect the residual stresses measurements. Adhesion between the coatings and substrate was analyzed using “Mercedes” testing.

Implant-induced strain-relaxation in SiGe/Si layers

1993 ◽  
Vol 51 ◽  
pp. 1112-1113
Author(s):  
N. David Theodore ◽  
Gordon Tam
Keyword(s):  
Integrated Circuits ◽  
Heterojunction Bipolar Transistors ◽  
High Speed ◽  
High Performance ◽  
Strain Relaxation ◽  
Base Material ◽  
Sige Layer ◽  
Bipolar Transistors ◽  
Leakage Currents ◽  
Extrinsic Base

SiGe is being extensively investigated for use in heterojunction bipolar-transistors (HBT) and high-speed integrated circuits. SiGe is typically used as an epitaxial base material in HBTs. To obtain extremely high-performance bipolar-transistors it is necessary to reduce the extrinsic base-resistance. This can be done by increasing the base-doping or by widening the base link-region by ion implantation. A problem that arises however with the use of implantation is that blanket implants have been found to enhance strain-relaxation of SiGe/Si. Strain relaxation will cause the bandgap-difference between Si and SiGe to decrease; this difference is maximum for a strained SiGe layer. The electrical benefits of using SiGe/Si arise largely from the presence of a significant bandgap-difference across the SiGe/Si interface. Strain relaxation reduces this benefit. Furthermore, once misfit or threading dislocations result (during strain-relaxation), the defects can give rise to recombination-generation in depletion regions of the device; high electrical leakage currents result.

scholarly journals High Performance Gear Hobbing with powder-metallurgical High-Speed-Steel

Procedia CIRP ◽  
2012 ◽  
Vol 1 ◽  
pp. 196-201 ◽  
Author(s):  
Bernhard Karpuschewski ◽  
Hans-Joachim Knoche ◽  
Martin Hipke ◽  
Martin Beutner
Keyword(s):  
High Speed ◽  
High Performance ◽  
High Speed Steel ◽  
Gear Hobbing

Sintered Valve Seat Inserts – Microstructural Characterisation

2006 ◽  
Vol 530-531 ◽  
pp. 65-70 ◽  
Author(s):  
E.S. Jesus Filho ◽  
Edilson Rosa Barbarosa Jesus ◽  
Lucio Salgado ◽  
S.L. Jesus ◽  
Marco Antonio Colosio ◽  
...  
Keyword(s):  
Heat Treatment ◽  
High Speed ◽  
Diffusion Mechanism ◽  
High Speed Steel ◽  
Heat Treatment Condition ◽  
Commercial Application ◽  
Valve Seat ◽  
Before And After ◽  
The Matrix ◽  
Valve Seat Inserts

This work presents aspects related to new sintered materials for valve seat inserts application. Two types of materials were evaluated. The materials were made using powder metallurgy technique from a basic mixture of high-speed steel (AISI M3/2), iron and carbide powders. The microstructures of these materials before and after heat treatment are presented. Under the heat treatment condition, the activation of the diffusion mechanism among phases was promoted and a better distribution of the Cu phases along the matrix was achieved. The results indicate that the materials under development have a potential for commercial application as valve seat inserts.

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