Steels for bearings

The mechanical properties of ex-situ and in-situ metallic glass matrix composites (MGMCs) have proven to be both scientifically unique and of potentially important for practical applications. However, the underlying deformation mechanisms remain to be studied. In this article, we review the development, fabrication, microstructures, and properties of MGMCs, including the room-temperature, cryogenic-temperature, and high-temperature mechanical properties upon quasi-static and dynamic loadings. In parallel, the deformation mechanisms are experimentally and theoretically explored. Moreover, the fatigue, corrosion, and wear behaviors of MGMCs are discussed. Finally, the potential applications and important unresolved issues are identified and discussed.

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Metallic glass matrix composites

https://docs.lib.purdue.edu/cgi/viewcontent.cgi?article=2056&context=nanopub

Fatigue Performance Improvement in AISI 4140 Steel by Dynamic Strain Aging and Dynamic Precipitation During Warm Laser Shock Peening

Bulk metallic glasses (BMGs) can exhibit excellent combinations of strength and fracture toughness that cannot be achieved by traditional metals, making them attractive for load bearing, mechanical engineering applications. Furthermore, recent research on BMGs has shown that many early perceived shortcomings, such as apparent brittleness or poor fatigue resistance, are not as big of a problem as once thought. The purpose of this paper is to review some of the unique mechanical characteristics of BMGs along with some of the strategies that may be used to improve or exploit their characteristics so that BMGs may be used as structural materials in engineering applications.

Bulk Metallic Glasses as Structural Materials: A Review

Direct Z-scheme anatase/rutile bi-phase nanocomposite TiO 2 nanofiber photocatalyst with enhanced photocatalytic H 2 -production activity

Stress-controlled load increase and constant amplitude tests have been carried out in a temperature range of -60°C < T < 20°C at the aluminium alloy AlMg4.5Mn (EN AW-5083). Therefore a recently developed climate chamber which operates with liquid nitrogen was mounted on a servo-hydraulic fatigue testing machine to realize the required low temperatures. Beside conventional mechanical hysteresis measurements, electrical resistance and temperature measurements are used to characterize the fatigue behavior. Furthermore, with these methods, the endurance limit was successfully estimated in a load increase test. Woehler curves were determined with constant amplitude tests at different temperatures. The conventionally determined endurance limit corresponds with the value from the load increase test.

Investigation of the Fatigue Behavior of AlMg4.5Mn (EN AW-5083) in the Temperature Range -60 °C < T < 20 °C

The mechanical properties of a unidirectional carbon/carbon (C/C) composite with a mainly highly textured matrix are investigated in tensile tests for the as-received state and after heat treatment from 1600 °C to 2500 °C. In order to interpret the composite behaviour single fibre tests, analyses of fracture surfaces and tests on infiltrated fibre felts were conducted. The fibre – matrix shear strength was determined by push-out indentation tests. Strength and ductility only change slightly although the strength of the fibres decreases significantly with increasing heat treatment temperature (HTT). The reason is a reduced bonding strength between fibre and matrix with increasing HTT. The Young’s modulus of C/C composites increases with HTT. The best mechanical properties of the composite are reached by finding a compromise between sufficient fibre strength and weakened fibre-matrix strength at a HTTof 1600 °C.

Analysis of failure behaviour of carbon/carbon composite made by chemical vapour infiltration considering fibre, matrix and interface properties Dedicated to Professor Eckard Macherauch on the occasion of the 80th anniversary of his birth

Investigation of the stress reduction and temperature increase due to ultrasonic vibrations with different amplitudes during compression tests of steels with varying specimen sizes.

Eberhard Kerscher

Papers

Investigation of the Fatigue Behavior of AlMg4.5Mn (EN AW-5083) in the Temperature Range -60 °C < T < 20 °C

Analysis of failure behaviour of carbon/carbon composite made by chemical vapour infiltration considering fibre, matrix and interface properties Dedicated to Professor Eckard Macherauch on the occasion of the 80th anniversary of his birth

Investigation of the stress reduction and temperature increase due to ultrasonic vibrations with different amplitudes during compression tests of steels with varying specimen sizes.

Mechanisches Verhalten Ausgewählter Werkstoffsysteme Verbundstranggepresster Leichtbauprofile Unter Quasistatischer Belastung

Influence of a thermomechanical treatment on the lifetime of a high strength steel in very high cycle fatigue