Copper Bearing HSLA Steel: Part One

The benefits of standard HSLA steels mean that materials with good combinations of strength toughness and weldability can be produced, all at a very reasonable cost.
During the early 20th century, experimentation began to see what impact copper would have as an alloying element. The results showed significant further improvement in the overall mechanical properties of the materials including a higher resistance to fatigue crack growth.
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Fatigue of Nickel-Based Superalloys: Part Two

It has been discovered that it is feasible to construct parts of nickel based superalloys for use at high stress in turbines and aircraft engines with greatly reduced crack propagation rates and with good high temperature strength. The properties needed for moving parts of the engine are usually greater than those needed for static parts, although the sets of needed properties are different for the different components of an engine.
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Fatigue of Nickel-Based Superalloys: Part One

A critical property of nickel-based superalloys is their resistance to fatigue-crack propagation, particularly at service temperatures.
Many nickel-based superalloys are subject to formation of cracks or incipient cracks, either in fabrication or in use, and that the cracks can actually propagate or grow while under stress during the use in structures such as gas turbines and jet engines.

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Spark Plasma Sintering

The SPS process is expected to find increased use in the fabrication of functionally graded materials (FGMs), intermetallic compounds, fiber reinforced ceramics (FRC), metal matrix composites (MMC) and nano crystalline materials, which are difficult to sinter by conventional sintering methods.
The major interest in this process, when the sintering parameters have been mastered, is linked to the extreme rapidity of the thermal treatment.

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