Chromium Addition Effect on Wear Properties of Cast-Iron Material

2015 ◽  
Vol 809-810 ◽  
pp. 572-577
Author(s):  
Costel Florea ◽  
Costică Bejinariu ◽  
Viorel Paleu ◽  
Daniela Chicet ◽  
Ioan Carcea ◽  
...  
Keyword(s):  
Cast Iron ◽  
Friction Coefficient ◽  
Point Of View ◽  
Material Surface ◽  
Wear Properties ◽  
Experimental Conditions ◽  
Disk Brake ◽  
Friction Regime ◽  
New Material ◽  
Iron Material

A new cast iron material with a higher Cr content than usual is analyzed by chemical, micro-structural and friction coefficient point of view. The material was obtained by classical melting and the results compared with the experimental results obtained from a standard cast-iron used for applicative disk brake. Four different mechanical solicitation rates were used on the same material surface and the same load. The solicitation regime can be considered as semi-liquid and similar to a raining day experimental conditions. In this paper no thermal considerations were present or discussed. The results present a bigger friction coefficient of the new material and further considerations are necessary for example in a different friction regime.

Wear Properties and Scuffing Resistance of the Cr–Al2O3 Coated Piston Rings: The Effect of Convexity Position on Barrel Surface

2018 ◽  
Vol 141 (2) ◽  
Author(s):  
Siqi Ma ◽  
Wenbin Chen ◽  
Chengdi Li ◽  
Mei Jin ◽  
Ruoxuan Huang ◽  
...  
Keyword(s):  
Cast Iron ◽  
Friction Coefficient ◽  
Surface Morphology ◽  
Pressure Distribution ◽  
Cylinder Liner ◽  
Wear Loss ◽  
Wear Properties ◽  
Piston Rings ◽  
Oil Film ◽  
Influencing Mechanism

This work investigates the effect of convexity position of ring barrel surface on the wear properties and scuffing resistance of the Cr–Al2O3 coated piston rings against with the CuNiCr cast iron cylinder liner. The scuffed surface morphology and elements distribution as well as the oil film edge were analyzed to explore the influencing mechanism of the convexity position on the scuffing resistance. The results show that the convexity offset rate on the barrel surface of the ring has no noticeable influence on both friction coefficient and wear loss near the dead points, but a suitable convexity position will result in the improved scuffing resistance. The shape of the barrel face not only affects the worn area on the ring, but also determines the oil film wedge and pressure distribution, consequently influences the scuffing resistance.

scholarly journals Bifilm Defects in Ti-Inoculated Chromium White Cast Iron

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3124
Author(s):  
Malwina Dojka ◽  
Marcin Stawarz
Keyword(s):  
Cast Iron ◽  
White Cast Iron ◽  
Crystallization Front ◽  
Point Of View ◽  
Austenitic Matrix ◽  
Wear Properties ◽  
The Impact ◽  
Chromium Cast Iron ◽  
Titanium Compounds ◽  
White Chromium

In recent years, white chromium cast iron has gained a well-settled position among wear-resistant materials. In recent times, chromium cast iron samples containing titanium have attracted attention. In cast iron samples, titanium combines with carbon and forms TiC particles, which may be form a crystallization underlay for eutectic M7C3 carbides and austenite. Accordingly, the inoculation process occurring in the crystallizing alloy should result in the proper, regular distribution of fine eutectic chromium carbides in the austenitic matrix. The presented research was conducted on 20% Cr hypoeutectic white cast iron with the addition of 0.5, 1, and 2% of Ti. Ti inoculation and the presence of TiC allowed for superior wear properties to be obtained. However, the conducted study revealed a significant decrease in the impact strength of examined alloys, especially for the cast iron samples with a high amount of Ti, in which the TiC compounds agglomerated. Titanium compounds accumulate in clusters and their distribution is irregular. Most of the TiC compounds were transported by the crystallization front into the center of the castings, where micropores were formed, meaning they were no longer effective crystallization underlays. In the authors’ opinion, the agglomerate formation is strictly connected with the appearance of bifilm defects in the casting microstructure. The conducted research shows how an incorrect volume of an additive may have negative influences on the properties of the casting. This is a vital issue not only from a technological point of view, but also for economic reasons.

A Study on Wear Properties of GCV Material with DLC Coating

2013 ◽  
Vol 470 ◽  
pp. 7-10
Author(s):  
Ki Woo Nam ◽  
Soo Chul Lee
Keyword(s):  
Cast Iron ◽  
Friction Coefficient ◽  
Coating Layer ◽  
Wear Test ◽  
High Hardness ◽  
Wear Properties ◽  
Dlc Coating ◽  
Insulating Properties ◽  
Partial Damage ◽  
Grey Iron

Compacted vermicular (CV) graphitization cast iron is the name given to graphitization cast iron where the shape of the graphite looks like a vermicular. Castability and the thermal conductivity of CV graphitization cast iron is similar to those of Grey iron, while the strength of CV graphitization cast iron is similar to that of ductile iron. The thin film of diamond-like carbon (DLC) is one of the amorphous carbon thin films. It has various characteristics which are similar to those of diamond, such as high hardness, lubricity, abrasion resistance, chemical stability, electrical insulating properties and optical transparency. In this study, wear characteristics of Graphite Compacted Vermicular (GCV) material were investigated in accordance with changes in DLC coating time. The obtained results are as follows: the microstructure of GCV340 showed complex tissue with eccentric graphite and spherical graphite. The friction coefficient shows under 0.2 in all specimens. After enduring the wear test until 2000 m, the coating layer of the DLC coating specimen of 90 minute hardly showed any damage. It had only partial damage after taking the wear test until 2000 m. The friction coefficient was also the lowest.

scholarly journals Electro-chemical Corrosion of a Cast Iron Protected with a Al2O3 Ceramic Layer

2019 ◽  
Vol 69 (12) ◽  
pp. 3586-3589 ◽  
Author(s):  
Costica Bejinariu ◽  
Corneliu Munteanu ◽  
Costel Dorel Florea ◽  
Bogdan Istrate ◽  
Nicanor Cimpoesu ◽  
...  
Keyword(s):  
Cast Iron ◽  
Electrolyte Solution ◽  
Metallic Substrate ◽  
Thin Layers ◽  
Ceramic Layer ◽  
Material Surface ◽  
Chemical Corrosion ◽  
Al2o3 Ceramic ◽  
Micro Cracks ◽  
Iron Material

Thin layers of Al2O3 were used to protect a standard FC250 cast iron at electro-corrosion in acid rain electrolyte solution. In comparison with a cast-iron material we present the results obtained on the metallic covered sample using linear and cyclic potentiometry. The material surface was investigated using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) techniques. The results present a generalized corrosion with a higher resistance for covered samples (more than 30 times) in comparison with the simple cast iron. The main causes of the corrosion of the covered samples are based on the thin ceramic layer imperfections like pores or micro-cracks that facilitate the contact of the electrolyte solution with the metallic substrate.

Research on Tribological Properties of Cast Iron at High-Speed Dry Sliding Condition

2014 ◽  
Vol 936 ◽  
pp. 2063-2067
Author(s):  
Chen Yue ◽  
Shang Guan Bao ◽  
Ying Yu Huang
Keyword(s):  
Cast Iron ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Abrasive Wear ◽  
Tribological Properties ◽  
High Speed ◽  
Friction Material ◽  
Dry Sliding ◽  
Oxidative Wear ◽  
Wear Properties

The friction and wear properties of cast iron with different graphite morphologies and matrix microstructure were investigated at high speed dry sliding against GCr15 steel on the MMS-1G high-speed tribometer apparatus. The various wear micro-mechanisms and tribo-metallographic phases were studied by using scanning electron microscopy. The results show that as friction material, vermicular iron exhibits excellent comprehensive tribological properties. The friction coefficient of cast iron sliding against GCr15 decreases while the wear rate increases with the increase of sliding speed, friction coefficient and wear rate decline with the increase of pearlite content. Under the experimental condition, the main wear mechanisms of flake iron are abrasive wear, of vermicular iron are abrasive wear and oxidative wear and of nodular iron are oxidative wear, abrasive wear and fatigue spalling.

Micro-Thermal Field-Flow Fractionation

2002 ◽  
Vol 67 (11) ◽  
pp. 1596-1608 ◽  
Author(s):  
Josef Janča
Keyword(s):  
High Performance ◽  
Thermal Field ◽  
Temperature Drop ◽  
Point Of View ◽  
Constant Field ◽  
Field Flow Fractionation ◽  
Operational Mode ◽  
Experimental Conditions ◽  
Standard Size ◽  
Flow Fractionation

The effect of miniaturization of the separation channel on the performance of thermal field-flow fractionation (TFFF) is substantiated theoretically. The experiments carried out under carefully chosen experimental conditions proved the high performance of the separation of polymers within an extended range of molar masses from relatively low up to ultrahigh-molar-mass (UHMM) samples. The new micro-TFFF allows to achieve high resolution when applying constant field force operation, it makes easy the programming of the temperature drop which is an advantageous operational mode from the point of view of the time of analysis, and it extends considerably the range of perfectly controlled temperature of the cold wall due to a substantial decrease in the heat energy flux compared with standard size channels.

scholarly journals Vibroacoustic Assessment of an Innovative Composite Material for the Roof of a Coupe Car

2021 ◽  
Vol 11 (3) ◽  
pp. 1128
Author(s):  
Nunziante Cascone ◽  
Luca Caivano ◽  
Giuseppe D’Errico ◽  
Roberto Citarella
Keyword(s):  
Composite Material ◽  
Transfer Functions ◽  
Realistic Model ◽  
Point Of View ◽  
Damping Capacity ◽  
Geometry Structure ◽  
Fiberglass Composite ◽  
New Material ◽  
Static Rigidity ◽  
Innovative Material

The objective of this paper is the vibroacoustic evaluation of an innovative material for a sports car roof, aiming at replacing fiberglass composite materials. Such evaluation was carried out using numerical and experimental analysis techniques, with cross-comparison between the corresponding results. The innovative material under analysis is a composite material, with a thermoplastic polypropylene matrix and reinforcement made of cellulose fibers. In order to validate the virtual dynamic modeling of the new material, the inertance on different points of some sheets made of the material under analysis was evaluated by an in-house made experimental activity, performed in the CRF (Fiat Research Center) test room, and cross-compared with corresponding results from a numerical analysis performed with the MSC Nastran software. Then, a realistic model of the car roof of the Alfa Romeo 4C car, made with the new material, was implemented and analyzed from the vibroacoustic point of view. The mere switch to the new material, with no changes in the geometry/structure of the car roof, did not allow preserving the original values of static rigidity, dynamic rigidity, and configuration of modal shapes. For this reason, a geometric/structural optimization of the component was performed. Once the new geometry/structure was defined, a vibroacoustic analysis was carried out, checking for a possible coupling between the fluid cavity modes and the structure car body modes. Finally, the vibroacoustic transfer functions to the driver’s ear node were assessed, considering two different excitation points on the structure. The excellent damping capacity of the proposed material led to an improvement in the vibroacoustic transfer functions and to a reduction in the weight of the pavilion.

scholarly journals The Effect of Water Concentration in Ethyl Alcohol on the Environmentally Assisted Embrittlement of Austempered Ductile Irons

Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 94
Author(s):  
Petar Janjatovic ◽  
Olivera Eric Cekic ◽  
Leposava Sidjanin ◽  
Sebastian Balos ◽  
Miroslav Dramicanin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Cast Iron ◽  
Ultimate Tensile Strength ◽  
Ethyl Alcohol ◽  
Water Concentration ◽  
Different Types ◽  
Influence Of Water ◽  
Iron Material ◽  
Proof Strength

Austempered ductile iron (ADI) is an advanced cast iron material that has a broad field of application and, among others, it is used in contact and for conveyance of fluids. However, it is noticed that in contact with some fluids, especially water, ADI material becomes brittle. The most significant decrease is established for the elongation. However, the influence of water and the cause of this phenomenon is still not fully understood. For that reason, in this paper, the influence of different water concentrations in ethyl alcohol on the mechanical properties of ADI materials was studied. The test was performed on two different types of ADI materials in 0.2, 4, 10, and 100 vol.% water concentration environments, and in dry condition. It was found that even the smallest concentration of water (0.2 vol.%) causes formation of the embrittled zone at fracture surface. However, not all mechanical properties were affected equally and not all water concentrations have been critical. The highest deterioration was established in the elongation, followed by the ultimate tensile strength, while the proof strength was affected least.

scholarly journals Three-dimensional CFD modeling of thermal behavior of a disc brake and pad for an automobile

2020 ◽  
Vol 15 (4) ◽  
pp. 543-549
Author(s):  
Haydar Kepekci ◽  
Ergin Kosa ◽  
Cüneyt Ezgi ◽  
Ahmet Cihan
Keyword(s):  
Cast Iron ◽  
Friction Coefficient ◽  
Elevated Temperatures ◽  
Gray Cast Iron ◽  
Three Dimensional ◽  
Brake System ◽  
Gray Cast ◽  
Cfd Modeling ◽  
Disc Brake ◽  
Disc Material

Abstract The brake system of an automobile is composed of disc brake and pad which are co-working components in braking and accelerating. In the braking period, due to friction between the surface of the disc and pad, the thermal heat is generated. It should be avoided to reach elevated temperatures in disc and pad. It is focused on different disc materials that are gray cast iron and carbon ceramics, whereas pad is made up of a composite material. In this study, the CFD model of the brake system is analyzed to get a realistic approach in the amount of transferred heat. The amount of produced heat can be affected by some parameters such as velocity and friction coefficient. The results show that surface temperature for carbon-ceramic disc material can change between 290 and 650 K according to the friction coefficient and velocity in transient mode. Also, if the disc material gray cast iron is selected, it can change between 295 and 500 K. It is claimed that the amount of dissipated heat depends on the different heat transfer coefficient of gray cast iron and carbon ceramics.

Sign in / Sign up

Export Citation Format

Share Document