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Strengthening Mechanisms in Steels
Published in Vladimir B. Ginzburg, Metallurgical Design of Flat Rolled Steels, 2020
In dilute solid solutions, the amount of hardening is roughly proportional to the concentration of the alloying element; if more than one solute element is present, the total hardening is approximately the sum of the characteristic effects of each element taken alone. The strengthening and hardening that result from a given alloying element in solid solution depend on the differences in atom size and electronic structure between it and the solvent metal. Based on the differences in atom size and electronic structure between it and the solvent metal, the solid-solution strengthening is divided in two types: Solid-solution strengthening by substitutional elementsSolid-solution strengthening by interstitial elements.
High Entropy Alloys
Published in T.S. Srivatsan, Manoj Gupta, High Entropy Alloys, 2020
Rohit R. Shahi, Rajesh K. Mishra
Severe lattice distortion suggests that the crystalline structure in HEAs is deformed. The lattice in HEAs is composed of different sizes of atoms, and the difference in atomic size generates the distortion. This impedes the dislocation movements and leads to solid-solution strengthening. The severe lattice distortion effectively decreases the electrical and thermal conductivity because it markedly increases the scattering of propagating electrons and phonons [10].
Strengthening Mechanisms in Metals
Published in Zainul Huda, Metallurgy for Physicists and Engineers, 2020
Solid-solution strengthening refers to the strengthening caused by the presence of solute atoms in a crystal lattice. It occurs when the atoms of the new element (solute) form a solid solution with the base metal (solvent), but there is still only one phase. The presence of solute atoms in a crystal lattice causes strain and distortion in the lattice; hence greater shear stress is required to move dislocations through the lattice. This is why an alloy is generally stronger than pure metal. For example, the tensile strength of an aluminum alloy containing 2% Mg is around 75 MPa as compared to 30 MPa for pure aluminum. In general, higher the concentration of an alloying element, greater will be the strengthening contribution of the alloying element to the alloy.
Mechanical and damping behavior of artificially aged Al 6061/TiO2 reinforced composites for aerospace applications
Published in Particulate Science and Technology, 2023
Olusegun Adebayo Ogunsanya, Abayomi Adewale Akinwande, Oluwatosin Abiodun Balogun, Valentin Romanovski, M. Saravana Kumar
For the as-cast alloy, it had the least hardness as shown in Figure 6. The material in the as-cast condition is a relatively soft matrix. The improvement in strength achieved by solid solution strengthening is small because the solubility limits of the alloying elements are limited at room temperature; this means that very little strength is obtainable. At applied stress, dislocations easily cut through the matrix and continue their path along with slip directions because of the weak alloy matrix. For the aged Al6061 alloy, the strengthening created by aggregated second-phase particles is usually additional to the alloy. The enhanced hardness upon age-hardening is a result of high densities of precipitates. The precipitates induce huge strain in the surrounding lattice by causing some distortions in the matrix, which impede dislocation slip. However, the second phase particles resist the slip process, thus increasing strength (Rathod and Menghani 2021; Gurumurthy et al. 2021; Kostryzhev 2021).
Microstructure and mechanical behavior assessment of Al–Cu composites fabricated through stir casting
Published in Particulate Science and Technology, 2018
S. Madhusudan, M. M. M. Sarcar, N. R. M. R. Bhargava
Figure 6 shows the comparison of specific strength and strain for alloy and the composite having same composition. Alloy has shown specific strength of 50 MPa, whereas composite 45 MPa. Xiandong et al. (1997) reported that the room-temperature conventional mechanical properties for composites were slightly decreased as compared with those of matrix alloys, and still remained at a relative high level for a particular value of particle fraction. Solid solution strengthening and presence of intermetallics makes the alloy stronger. Whereas in composite though same percentage of copper is present but it is in particle form. However, there is a possibility of alloy formation at the interface due to diffusion of copper in Al matrix. But this effect is nominal because the stir time given is less during manufacturing to restrict the mutual solubility. Hence, composite strengthening is due to the presence of reinforcement, limited alloy formation at the interface. Drop in strain is observed for composite as compared with alloy. Barmouz, Givi, and Sayfi (2011) concluded that MMC produced by friction stir process showed lower strength and elongation than pure Cu, while a remarkable elongation was observed for specimens without SiC particles. The obtained results are in tune with the above statement and hence composite phenomena can be attributed. Figure 7 shows the SEM image of the alloy. Dimple structure can be seen from the figures. Particles’ pull out can be seen from fracture surface of the composite (Figure 8).
A first step towards computational design of W-containing self-healing ferritic creep resistant steels
Published in Science and Technology of Advanced Materials, 2020
Hao Yu, Wei Xu, Sybrand van der Zwaag
Solid solution strengthening works by adding atoms of alloying element to the crystalline lattice of the base metal, forming a solid solution. The local nonuniformity in the lattice due to the alloying element makes plastic deformation more difficult by impeding dislocation motion through stress fields, and thereby improves the yield strength of the material. The amount of solid solution strengthening depends on both the chemical nature of the solute atom and the maximum concentration which can be brought into solid solution. The solid solution strengthening factor (SSS) was then taken to be the weighted contribution of atomic concentration of solutes, which can be formulated as