Wear Characteristics of Vacuum Sintered Steels

2011 ◽  
Vol 672 ◽  
pp. 17-22 ◽  
Author(s):  
Mario Rosso ◽  
Eva Dudrová ◽  
Marco Actis Grande ◽  
Róbert Bidulský
Keyword(s):  
Chemical Composition ◽  
Processing Condition ◽  
Surface Hardness ◽  
Wear Behaviour ◽  
Vacuum Furnace ◽  
Processing Conditions ◽  
Wear Characteristics ◽  
Sintered Steels ◽  
Pin On Disk ◽  
Disk Test

The present paper is focused on the wear characteristic of vacuum sintered Cr-Mo-[Mn]-[Cu] steels. The effect of chemical composition and the processing conditions in a vacuum furnace were evaluated. In such furnaces the cooling rate is generally determined by the pressure of the gas (N2) introduced into the chamber, the average cooling rates were calculated in the range of 1240°C to 400°C. The wear characteristics were analyzed as function of the processing and microstructures of the tested alloys through pin on disk test. Sintering of specimens in vacuum together with rapid cooling resulted in the formation of dominant martensitic microstructures with some small bainitic areas. The effect of both surface hardness and microstructure on the wear behaviour of the investigated steels shows the relation between the hardness and the wear rate. The influence of processing condition on the amount of martensite is also presented.

Comparison of Structure and Wear Properties of Fine-Structured WC-CoCr Coatings Deposited by HVOF and HVAF Spraying Processes

2012 ◽  
Vol 188 ◽  
pp. 422-427 ◽  
Author(s):  
Iosif Hulka ◽  
Viorel Aurel Şerban ◽  
Kari Niemi ◽  
Petri Vuoristo ◽  
Johannes Wolf
Keyword(s):  
High Velocity ◽  
Wear Behaviour ◽  
Tungsten Carbides ◽  
X Ray Diffraction ◽  
Wear Properties ◽  
Fuel Gas ◽  
Cermet Powder ◽  
Pin On Disk ◽  
Oxygen Fuel ◽  
Disk Test

The aim of the work was to study the microstructure and wear properties of fine-structured HVOF and HVAF sprayed WC-10Co-4Cr coatings prepared from powder having submicron-sized tungsten carbides. The coatings were deposited by HVOF (High Velocity Oxygen Fuel) and HVAF (High Velocity Air Fuel) using propane as a fuel gas in both processes, and using oxygen or air as oxidizing gas for combustion, respectively. Nitrogen was used as carrier gas for the powder. Commercially available agglomerated and sintered cermet powder with main carbide sizes under 500 nm was used in this study. Scanning electron microscopy (SEM) and X-ray diffraction were performed in order to characterize the powder and the microstructures formed during the spraying processes. The microhardness HV0.3 of the coatings was investigated and the pin on disk test was used to determine the sliding wear behaviour. The rubber wheel abrasion test was performed in order to determine the abrasion wear resistance of the coatings.

Wear Characteristics of Metals Using Disk on Disk Type Wear Test Rig

2005 ◽  
Author(s):  
K. Hiratsuka ◽  
T. Yoshida
Keyword(s):  
Contact Time ◽  
Adhesive Wear ◽  
Wear Test ◽  
Test Rig ◽  
Wear Characteristics ◽  
Dissimilar Metal ◽  
Emery Paper ◽  
Type Test ◽  
Pin On Disk ◽  
Disk Test

Wear of metals is influenced by many factors such as material, surrounding atmosphere and sliding conditions. Besides these factors, type of the wear test also has a significant effect on wear results. For example, when pin on disk test rig is used, wear of disk is usually more than that of pin [1]. This is because the contact time of each specimen is asymmetric. In this case, the transfer particle at the tip of the pin protects pin against wear. So the wear of dissimilar metals depends on the pin-disk combination. In order to fully characterize the adhesive wear, we have developed a disk on disk type test rig [2]. In this rig, the circumferential surfaces of the two identical disks are in sliding contact thereby resulting in a symmetrical contact. In this paper, the wear characteristics of ten different metals sliding against emery paper as well as against themselves have been presented along with the wear of 43 dissimilar metal combinations.

Microstructure, Fracture and Mechanical Properties of ECAPed Aluminum P/M Alloy with Respect to the Porosity

2014 ◽  
Vol 783-786 ◽  
pp. 108-113 ◽  
Author(s):  
Jana Bidulská ◽  
Robert Bidulský ◽  
Marco Actis Grande
Keyword(s):  
Mechanical Properties ◽  
Processing Condition ◽  
Stress Axis ◽  
Tensile Fracture ◽  
Vacuum Furnace ◽  
Processing Conditions ◽  
Plane Normal ◽  
Quantitative Image ◽  
Sintering Processes ◽  
Sintered Materials

The main aim of this paper is to investigate the effects of different processing conditions on the behavior of a P/M (Powder Metallurgy) aluminum alloy with respect to the microstructure, fracture and mechanical properties. Moreover, the evolution of porosity as a consequence of pressing, sintering and ECAPing processes was investigated. A commercial Al-Mg-Si-Cu-Fe powder was used as material to be investigated. Different compacting pressures (400, 500, 600, 700 MPa) were applied. Specimens were dewaxed in a ventilated furnace at 400 °C for 60 min before sintering. Sintering was carried out in a vacuum furnace at 610 °C for 30 min. The specimens were ECAPed for 1 pass. The 2-dimensional quantitative image analysis was carried out by means of SEM and OM for the evaluation of the dimensional and morphological porosity characteristics. The detailed microstructure revealed the main features of sintering processes as well as secondary pores at the prior alloying particle sites. The tensile fracture surfaces in both studied processing condition (as-sintered and ECAP) show limited ductility, with fracture occurring on a plane normal to the tensile stress axis. Examination at higher magnifications revealed predominantly transparticle ductile features. In terms of mechanical properties, ECAP is almost doubling the tensile strength of the as-sintered materials

scholarly journals WEAR CHARACTERISTICS OF Cu OFHC MATERIAL PREPARED BY ORBITAL FORGING AND ECAP

2010 ◽  
Vol 24 (06n07) ◽  
pp. 797-804
Author(s):  
R. BIDULSKÝ ◽  
M. ACTIS GRANDE ◽  
J. BIDULSKÁ ◽  
T. KVAČKAJ ◽  
T. DONIČ
Keyword(s):  
Thermal Conductivity ◽  
Wear Behaviour ◽  
Radial Forging ◽  
Processing Conditions ◽  
Wear Properties ◽  
Wear Characteristics ◽  
Equal Channel Angular Processing ◽  
Pin On Disc ◽  
Orbital Forging

The paper is focused on the wear mechanism of orbital forged and equal-channel angular extruded Cu OFHC (oxygen-free high thermal conductivity) material. The wear behaviour of the Cu OFHC material is investigated through pin-on-disc tests. Two different processing conditions have been used, equal-channel angular processing (ECAP) and orbital (radial) forging. The wear investigations in this orbital formed material are unique; additionally wear properties show interesting wear characteristics. Particular attention has also been paid to the friction coefficient and to the role of the wear rate.

scholarly journals Sintered Structural Steels Containing Mn, Cr And Mo – The Summary of the Investigations

2016 ◽  
Vol 16 (2) ◽  
pp. 59-85
Author(s):  
Maciej Sulowski
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Sintered Material ◽  
Structural Steels ◽  
Processing Conditions ◽  
Alloying Element ◽  
Sintering Atmosphere ◽  
Sintered Steels ◽  
Method Of Production ◽  
Better Than

AbstractThe paper is presented the development and method of production of modern, Ni-free sintered structural steels which contain carbide forming alloying elements (Cr) with high affinity for oxygen (Cr, Mn) and the much smaller additive of an expensive alloying element (Mo), enabling the production of structural sintered steels in commercial belt furnaces, using safe sintering atmospheres. The investigations reported deal with the analysis of microstructure and mechanical properties of these sintered structural steels produced in different processing conditions, especially modification of chemical composition of sintering atmosphere and also the connections between the microstructure of sintered material and its mechanical properties. This analysis was done to propose the appropriate chemical composition of sintered Ni-free steels with properties which are comparable or even better than those of sintered structural steels containing rich and carcinogenic nickel. The investigations of PM Mn- Cr-Mo steels were preceded by those on Mn steels.

scholarly journals Evaluation of Sliding Wear Behaviour for STD11 Coated with TiCN Using the Pin-on-Disk Test

2020 ◽  
Vol 967 ◽  
pp. 012061
Author(s):  
J H Bang ◽  
J H Song ◽  
G H Bae ◽  
N S Park ◽  
S O Choi ◽  
...  
Keyword(s):  
Sliding Wear ◽  
Wear Behaviour ◽  
Pin On Disk ◽  
Sliding Wear Behaviour ◽  
Disk Test

scholarly journals New Approach In The Properties Evaluation Of Ultrafine-Grained OFHC Copper

2015 ◽  
Vol 60 (2) ◽  
pp. 605-614 ◽  
Author(s):  
T. Kvačkaj ◽  
A. Kováčová ◽  
J. Bidulská ◽  
R. Bidulský ◽  
R. Kočičko
Keyword(s):  
Mechanical Properties ◽  
Strain Rate ◽  
Tensile Tests ◽  
Coarse Grained ◽  
Wear Behaviour ◽  
Ofhc Copper ◽  
Strain Rates ◽  
Ultrafine Grained ◽  
Reduction Of Area ◽  
Pin On Disk

AbstractIn this study, static, dynamic and tribological properties of ultrafine-grained (UFG) oxygen-free high thermal conductivity (OFHC) copper were investigated in detail. In order to evaluate the mechanical behaviour at different strain rates, OFHC copper was tested using two devices resulting in static and dynamic regimes. Moreover, the copper was subjected to two different processing methods, which made possible to study the influence of structure. The study of strain rate and microstructure was focused on progress in the mechanical properties after tensile tests. It was found that the strain rate is an important parameter affecting mechanical properties of copper. The ultimate tensile strength increased with the strain rate increasing and this effect was more visible at high strain rates$({\dot \varepsilon} \sim 10^2 \;{\rm{s}}^{ - 1} )$. However, the reduction of area had a different progress depending on microstructural features of materials (coarse-grained vs. ultrafine-grained structure) and introduced strain rate conditions during plastic deformation (static vs. dynamic regime). The wear behaviour of copper was investigated through pin-on-disk tests. The wear tracks examination showed that the delamination and the mild oxidational wears are the main wear mechanisms.

Predicting the wear coefficient and friction coefficient in dry point contact using continuum damage mechanics

2018 ◽  
Vol 233 (3) ◽  
pp. 447-455 ◽  
Author(s):  
Sahar Ghatrehsamani ◽  
Saleh Akbarzadeh
Keyword(s):  
Friction Coefficient ◽  
Damage Mechanics ◽  
Point Contact ◽  
Continuum Damage Mechanics ◽  
Continuum Damage ◽  
Wear Coefficient ◽  
Mechanics Model ◽  
Pin On Disk ◽  
Disk Test ◽  
The Continuum

Wear coefficient and friction coefficient are two of the key parameters in the performance of any tribo-system. The main purpose of the present research is to use continuum damage mechanics to predict wear coefficient. Thus, a contact model is utilized that can be used to obtain the friction coefficient between the contacting surfaces. By applying this model to the continuum damage mechanics model, the wear coefficient between dry surfaces is predicted. One of the advantages of using this model is that the wear coefficient can be numerically predicted unlike other methods which highly rely on experimental data. In order to verify the results predicted by this model, tests were performed using pin-on-disk test rig for several ST37 samples. The results indicated that the wear coefficient increases with increasing the friction coefficient.

Investigation of wear on the upper edges of webs of thin-film coated single-screw extruders processing pure polymers

2021 ◽  
Vol 63 (2) ◽  
pp. 143-150
Author(s):  
Torben Buttler ◽  
Jens Hamje ◽  
Rolf Reiter ◽  
Volker Wesling
Keyword(s):  
Wear Behavior ◽  
Cold Work ◽  
Polymer Processing ◽  
Chromium Nitride ◽  
Metallographic Examination ◽  
Test Speed ◽  
Single Screw Extruders ◽  
Pin On Disk ◽  
Screw Extruders ◽  
Disk Test

Abstract During polymer extrusion there are a variety of situations in which the screwthread of the extrusion screw has an unlubricated metal-to-metal contact with the barrel wall. At the same time the screw coating is subjected to the highest loads. The combination of a secondary hardening cold work steel 1.2379 and a chromium nitride coating deposited by ARC-PVD, which is frequently used in polymer processing, is characterized and investigated. The characterization is done by metallographic examination, SEM and CLSM. The tests were performed on a pin-on-disk and a pin-roll test rig. Different roughness levels were tested on the pin-on-disk test, where massive differences in wear behavior were found. A hybrid surface structure is proposed to optimize the tribosystem. On the pin-on-disk test stand, rollers made of the same material pairing were tested. The test speed was varied to highlight differences and similarities between the tribological systems. A wear minimization of 50 % was achieved and the similarities between the tribological systems were highlighted. In addition, the investigations led to the development of a new model thesis which provides a reason for the development of stippling on the screw when processing polycarbonate.

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