Introduction of a novel tribometer especially designed for scratch, adhesion and hardness investigation up to 1000℃

2016 ◽  
Vol 231 (4) ◽  
pp. 469-478 ◽  
Author(s):  
M Varga ◽  
M Flasch ◽  
E Badisch
Keyword(s):  
High Temperature ◽  
Cross Sections ◽  
Elevated Temperatures ◽  
Normal Load ◽  
Load Range ◽  
Aisi 304 ◽  
Fundamental Understanding ◽  
The Common ◽  
Scratch Tests ◽  
Application Specific

In order to gain a fundamental understanding of material behaviour at elevated temperatures a unique tribometer was designed which can operate at temperatures up to 1000℃. The test takes place in vacuum in order to avoid oxidation and the normal load range varies from 10 to 500 N. It is thus possible to describe the evolution of hardness over a broad range of temperatures and loads. This can give indications of possible microstructural modifications, which can be investigated afterwards on cross sections. For the characterisation of single abrasive phenomena on a very fundamental level, scratch tests at variable loads are proposed. The interaction of sliding surfaces can be simulated by adhesion testing. To this end an application specific counter body, e.g. taken from a field specimen, can be slid over the specimen surface at variable loads. Finally, it can be stated that this newly designed tribometer offers an enormous potential for deeper understanding of fundamental wear phenomena like ploughing, micro-breaking or adhesion occurring at high temperature. The possibilities of high temperature scratch and hardness testing with the new measurement system are shown on the common austenitic stainless steel 1.4301 (AISI 304).

TRIBOLOGICAL EVALUATION OF AL/TiB2/NANO-GR HYBRID COMPOSITES EXPOSED TO ELEVATED TEMPERATURE

2019 ◽  
Vol 27 (04) ◽  
pp. 1950132
Author(s):  
SUSWAGATA PORIA ◽  
GOUTAM SUTRADHAR ◽  
PRASANTA SAHOO
Keyword(s):  
High Temperature ◽  
Elevated Temperatures ◽  
Hybrid Composites ◽  
Operating Temperature ◽  
Normal Load ◽  
Dominant Role ◽  
Protective Layer ◽  
Stir Casting ◽  
Friction Behavior ◽  
Sem Images

High-temperature tribological behavior of hybrid Al/TiB2/nano-Gr composites is reported in this study. Fabrication of composites is done using ultrasonic cavitation assisted stir casting method. Cast composites are characterized through micro-hardness values, optical images and SEM images. Higher amount of nano-Gr incorporation reduces the hardness of hybrid composites. Effect of operating temperature on wear and friction behavior is studied for different hybrid ratios using a high-temperature tribo-tester over a temperature range of 50–250∘C and under normal load in the range of 25–75 N. Worn surfaces are characterized using FESEM images. EDX mapping of surfaces is done to observe the elements present on the surface after tribo-tests. Increase in the amount of reinforcement improves the wear resistance and friction behavior of composites at all temperatures. At lower operating load, wear rate of composites are found to be steady with increase in operating temperature. A protective layer enriched with nano-Gr particle is formed on the tribo-surface at higher temperature. Adhesion mechanism plays the dominant role in wear of hybrid composites at elevated temperatures.

High Temperature Corrosion in Refinery And Petrochemical Service

CORROSION ◽  
1960 ◽  
Vol 16 (12) ◽  
pp. 593t-600t ◽  
Author(s):  
E. N. SKINNER ◽  
J. F. MASON ◽  
J. J. MORAN
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Mechanical Behavior ◽  
Elevated Temperatures ◽  
High Temperature Corrosion ◽  
Residual Oil ◽  
The Common ◽  
Engineering Alloys ◽  
Corrosive Environments ◽  
Selection Of

Abstract The paper is concerned with the corrosion phenomena likely to influence the selection of materials for refinery service at elevated temperatures. The problems of oxidation, sulfidation and carburization are discussed in detail and consideration is given to the effects of condensate corrosion and residual oil ash corrosion. The contributions of various alloying elements in the common engineering alloys to their physical and mechanical behavior as well as to their corrosion resistance at elevated temperatures are discussed. Basic considerations for the selection of suitable alloys to withstand high temperature corrosive environments are outlined. 8.4.3

Development of a New Tip Assembly for Lateral Force Microscopy and Its Application to Thin Film Magnetic Media

1995 ◽  
Vol 117 (2) ◽  
pp. 244-249 ◽  
Author(s):  
C.-J. Lu ◽  
Zhaoguo Jiang ◽  
D. B. Bogy ◽  
T. Miyamoto
Keyword(s):  
Thin Film ◽  
Friction Coefficient ◽  
Normal Load ◽  
Lateral Force ◽  
Magnetic Media ◽  
Load Range ◽  
Force Microscopy ◽  
Normal Forces ◽  
Carbon Coated ◽  
Scratch Tests

In a Lateral Force Microscope (LFM), appropriate spring constants of the tip assembly are essential for obtaining proper normal loads for wear or scratch tests and good lateral force signals. We developed a new tip assembly design for which the lateral and normal springs can be changed independently. It was installed on a LFM where two optical heads are used to detect the lateral and normal deflections of the tip assembly for simultaneous measurements of the surface topography and friction force. Reliable calibration procedures for the LFM are presented. The LFM was used to measure the lateral forces in wear tests under various normal forces for thin film magnetic disks with and without a carbon overcoat. The friction coefficient is constant in the load range where there is no wear and increases with normal load after the tip starts to damage the surface. The carbon-coated disk has a lower friction coefficient and can support larger normal loads without wear.

High-Temperature Instability of A Cr2Nb-Nb(Cr) Microlaminate Composite

1996 ◽  
Vol 54 ◽  
pp. 374-375
Author(s):  
M. Larsen ◽  
R.G. Rowe ◽  
D.W. Skelly
Keyword(s):  
Heat Treatment ◽  
Solid Solution ◽  
High Temperature ◽  
Elevated Temperatures ◽  
Aircraft Engine ◽  
Lattice Parameter ◽  
Microstructural Stability ◽  
Elevated Temperature Strength ◽  
Cross Sectional ◽  
Bcc Structure

Microlaminate composites consisting of alternating layers of a high temperature intermetallic compound for elevated temperature strength and a ductile refractory metal for toughening may have uses in aircraft engine turbines. Microstructural stability at elevated temperatures is a crucial requirement for these composites. A microlaminate composite consisting of alternating layers of Cr2Nb and Nb(Cr) was produced by vapor phase deposition. The stability of the layers at elevated temperatures was investigated by cross-sectional TEM.The as-deposited composite consists of layers of a Nb(Cr) solid solution with a composition in atomic percent of 91% Nb and 9% Cr. It has a bcc structure with highly elongated grains. Alternating with this Nb(Cr) layer is the Cr2Nb layer. However, this layer has deposited as a fine grain Cr(Nb) solid solution with a metastable bcc structure and a lattice parameter about half way between that of pure Nb and pure Cr. The atomic composition of this layer is 60% Cr and 40% Nb. The interface between the layers in the as-deposited condition appears very flat (figure 1). After a two hour, 1200 °C heat treatment, the metastable Cr(Nb) layer transforms to the Cr2Nb phase with the C15 cubic structure. Grain coarsening occurs in the Nb(Cr) layer and the interface between the layers roughen. The roughening of the interface is a prelude to an instability of the interface at higher heat treatment temperatures with perturbations of the Cr2Nb grains penetrating into the Nb(Cr) layer.

Phase transformation and layer evolution in molybdenum disilicide-silicon carbide nanolayered coatings

1994 ◽  
Vol 52 ◽  
pp. 538-539
Author(s):  
H. Kung ◽  
T. R. Jervis ◽  
J.-P. Hirvonen ◽  
M. Nastasi ◽  
T. E. Mitchell ◽  
...  
Keyword(s):  
Phase Transformation ◽  
High Temperature ◽  
Oxidation Resistance ◽  
Elevated Temperatures ◽  
Matrix Material ◽  
Molybdenum Disilicide ◽  
High Temperature Strength ◽  
Cross Sectional ◽  
Good Oxidation Resistance ◽  
Structural Applications

MoSi2 is a potential matrix material for high temperature structural composites due to its high melting temperature and good oxidation resistance at elevated temperatures. The two major drawbacksfor structural applications are inadequate high temperature strength and poor low temperature ductility. The search for appropriate composite additions has been the focus of extensive investigations in recent years. The addition of SiC in a nanolayered configuration was shown to exhibit superior oxidation resistance and significant hardness increase through annealing at 500°C. One potential application of MoSi2- SiC multilayers is for high temperature coatings, where structural stability ofthe layering is of major concern. In this study, we have systematically investigated both the evolution of phases and the stability of layers by varying the heat treating conditions.Alternating layers of MoSi2 and SiC were synthesized by DC-magnetron and rf-diode sputtering respectively. Cross-sectional transmission electron microscopy (XTEM) was used to examine three distinct reactions in the specimens when exposed to different annealing conditions: crystallization and phase transformation of MoSi2, crystallization of SiC, and spheroidization of the layer structures.

WIELAND-K88

Alloy Digest ◽  
2005 ◽  
Vol 54 (12) ◽  
Keyword(s):  
Thermal Conductivity ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Stress Relaxation ◽  
Copper Alloy ◽  
Elevated Temperatures ◽  
Heat Treating ◽  
Relaxation Resistance ◽  
Temperature Performance ◽  
Very High

Abstract Wieland K-88 is a copper alloy with very high electrical and thermal conductivity, good strength, and excellent stress relaxation resistance at elevated temperatures. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: CU-738. Producer or source: Wieland Metals Inc.

DOWMETAL HZ32XA

Alloy Digest ◽  
1956 ◽  
Vol 5 (7) ◽  
Keyword(s):  
High Temperature ◽  
Physical Properties ◽  
Creep Resistance ◽  
Zirconium Alloy ◽  
Elevated Temperatures ◽  
Heat Treating ◽  
High Temperature Creep ◽  
Aged Condition ◽  
Chemical Company ◽  
Temperature Performance

Abstract DOWMETAL HZ32XA is a magnesium-thorium-zinc-zirconium alloy having good high temperature creep resistance, and is recommended for applications at elevated temperatures. It is used in the artificially aged condition (T5). This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as creep. It also includes information on high temperature performance as well as heat treating, machining, and joining. Filing Code: Mg-26. Producer or source: The Dow Chemical Company.

UDIMET 105

Alloy Digest ◽  
1972 ◽  
Vol 21 (7) ◽  
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Surface Treatment ◽  
Elevated Temperatures ◽  
Base Alloy ◽  
Heat Treating ◽  
Nickel Base Alloy ◽  
Temperature Performance ◽  
Nickel Base

Abstract UDIMET 105 is a nickel-base alloy which was developed for service at elevated temperatures. 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, joining, and surface treatment. Filing Code: Ni-175. Producer or source: Special Metals Corporation.

CARPENTER L-605 ALLOY

Alloy Digest ◽  
1987 ◽  
Vol 36 (8) ◽  
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Elevated Temperatures ◽  
Base Alloy ◽  
High Strength ◽  
Heat Treating ◽  
Temperature Performance ◽  
Cobalt Base Alloy ◽  
Cobalt Base ◽  
Oxidation And Corrosion

Abstract CARPENTER L-605 alloy is a nonmagnetic cobalt-base alloy that has good oxidation and corrosion resistance and high strength at elevated temperatures. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as creep and fatigue. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Co-81. Producer or source: Carpenter.

FANSTEEL 85 METAL

Alloy Digest ◽  
1981 ◽  
Vol 30 (6) ◽  
Keyword(s):  
High Temperature ◽  
Physical Properties ◽  
Creep Strength ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Base Alloy ◽  
Heat Treating ◽  
Good Combination ◽  
Bend Strength ◽  
Temperature Performance

Abstract FANSTEEL 85 METAL is a columbium-base alloy characterized by good fabricability at room temperature, good weldability and a good combination of creep strength and oxidation resistance at elevated temperatures. Its applications include missile and rocket components and many other high-temperature parts. This datasheet provides information on composition, physical properties, microstructure, hardness, elasticity, tensile properties, and bend strength as well as creep. It also includes information on low and high temperature performance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Cb-7. Producer or source: Fansteel Metallurgical Corporation. Originally published December 1963, revised June 1981.

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