Quantification of precipitation hardening is a challenging subject as it demands combined knowledge of precipitation strengthening mechanism and precipitate growth/coarsening kinetics. Having not seen many attempts on developing new theories in recent years, the authors are aware of the fact that many existing concepts and developed theories are sometimes even neglected or misused. This article...

Precipitation hardening, because it involves the hardening of the material over a prolonged time, is also called age hardening, or ageing. By the appropriate heat treatment of precipitation hardening, the strength or hardness of some heat-treatable aluminium alloys can be enhanced by the formation of nano-meter sized second-phase precipitated particles within the original phase matrix. The fine...

Microstructures and mechanical properties of equal-channel angular pressing (ECAP) processed and naturally aged ultrafine grained (UFG) and coarse grained (CG) 7075 Al alloys as well as their evolutions during annealing were investigated. After the same natural aging, the tensile yield strength, ultimate strength, and microhardness of the UFG samples were 103%, 35%, and 48% higher, respectively...

Precipitation hardening, or age hardening, provides one of the most widely used mechanisms for the strengthening of metal alloys. The fundamental understanding and basis for this technique was established in early work at the U. S. Bureau of Standards on an alloy known as Duralumin [1,2]. Duralumin is an aluminum alloy containing copper and magnesium with small amounts of iron and silicon. In a...

aa8090 is an extra light and deformable group of lithium containing aluminum alloys which have recently replaced some aerospace aluminum alloys, such as 2000 and 7000 series, due to their higher elastic modulus and lower specific weight. in this study, aa8090 matrix composites containing 3, 6 and 9 vol.% sic were cast using a modified stir casting method. the casting billets were deformed thoug...

The precipitation of nanoparticles plays a key role in determining the properties of many structural materials, and the understanding of their formation and stabilization mechanisms has been a long standing interest in the material field. However, the critical issues involving the group precipitation of various nanoparticles and their cooperative hardening mechanism remain elusive in the newly ...

Microstructural and mechanical properties of precipitation-hardened maraging steel could be stated on a basis of magnetic properties of such a material. A correlation between mechanical and magnetic properties of the maraging steel is treated from the view of non-destructive testing during and after heat treatment as well as during use under unfavourable conditions at elevated operating tempera...

x-ray diffraction peak profile analysis was used to identify changes in the lattice distortions during isothermal aging of fe-10ni-7mn (wt. %) maraging steel. integral peak breadths were analyzed using classical williamson-hall equation taking the elastic anisotropy into account. it was found that substantial lattice distortions rise during precipitation hardening which depend strongly on the s...