scholarly journals Effect of Heat Treatment on the Microstructure, Phase Distribution, and Mechanical Properties of AlCoCuFeMnNi High Entropy Alloy

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Gulhan Cakmak
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Yield Strength ◽  
Phase Distribution ◽  
Cast Alloy ◽  
Lattice Parameters ◽  
High Entropy Alloy ◽  
Second Phase ◽  
High Entropy ◽  
Heat Treated

The present paper reports the synthesis of AlCoCuFeMnNi high entropy alloy (HEA) with arc melting process. The as-cast alloy was heat treated at 900°C for 8 hours to investigate the effect of heat treatment on the structure and properties. Microstructural and mechanical properties of the alloy were analyzed together with the detailed phase analysis of the samples. The initially as-cast sample was composed of two separate phases with BCC and FCC structures having lattice parameters of 2.901 Å and 3.651 Å, respectively. The heat-treated alloy displays microsized rod-shaped precipitates both in the matrix and within the second phase. Rietveld refinement has shown that the structure was having three phases with lattice parameters of 2.901 Å (BCC), 3.605 Å (FCC1), and 3.667 Å (FCC2). The resulting phases and distribution of phases were also confirmed with the TEM methods. The alloys were characterized mechanically with the compression and hardness tests. The yield strength, compressive strength, and Vickers hardness of the as-cast alloy are 1317 ± 34 MPa, 1833 ± 45 MPa, and 448 ± 25 Hv, respectively. Heat treatment decreases the hardness values to 419 ± 26 Hv. The maximum compressive stress of the alloy increased to 2123 + 41 MPa while yield strength decreased to 1095 ± 45 with the treatment.

Microstructure and Mechanical Properties of Equitomic CoCrFeCuNi High Entropy Alloy

2018 ◽  
Vol 765 ◽  
pp. 149-154 ◽  
Author(s):  
Seung Min Oh ◽  
Sun Ig Hong
Keyword(s):  
Mechanical Properties ◽  
Yield Strength ◽  
Cold Rolling ◽  
Cast Alloy ◽  
Cold Work ◽  
High Entropy Alloy ◽  
Second Phase ◽  
Rich Phase ◽  
High Entropy ◽  
Microstructure And Mechanical Properties

Microstructure and mechanical properties of cast and cold-rolled equitomic CoCrFeCuNi alloy in which Mn was substituted by Cu from Cantor alloy was studied. The separation into two solid solutions (Cr-Co-Fe rich and Cu-rich phases) were observed in CoCrFeCuNi. Coarsening and widening of interdendritic Cu-rich phase after homogenization was observed after homogenization, suggesting Cu-rich phase is thermodynamically stable. The compressive stress-strain curves of homogenized cast CoCrFeCuNi alloy exhibited the reasonably high strength and excellent deformability for the cast alloy. The yield strength increased up to 960MPa after cold rolling from 265MPa of the homogenized cast alloy. The significant increase of yield strength is thought to be associated with the alignment of Cu-rich second phase in addition to cold work dislocation storage after cold rolling.

Effect of Nd Content and Heat Treatment on Microstructure and Mechanical Properties of Mg-Zn-Nd Alloy

2017 ◽  
Vol 898 ◽  
pp. 124-130 ◽  
Author(s):  
Shu Min Xu ◽  
Xin Ying Teng ◽  
Xing Jing Ge ◽  
Jin Yang Zhang
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Grain Size ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Cast Alloy ◽  
Second Phase ◽  
Casting Method ◽  
Magnesium Matrix ◽  
Microstructure And Mechanical Properties

In this paper, the microstructure and mechanical properties of the as-cast and heat treatment of Mg-Zn-Nd alloy was investigated. The alloy was manufactured by a conventional casting method, and then subjected to a heat treatment. The results showed that the microstructure of as-cast alloy was comprised of α-Mg matrix and Mg12Nd phase. With increase of Nd content, the grain size gradually decreased from 25.38 μm to 9.82 μm. The ultimate tensile strength and elongation at room temperature of the Mg94Zn2Nd4 alloy can be reached to 219.63 MPa and 5.31%. After heat treatment, part of the second phase dissolved into the magnesium matrix and the grain size became a little larger than that of the as-cast. The ultimate tensile strength was declined by about 2.5%, and the elongation was increased to 5.47%.

scholarly journals Effect of Microstructures and Mechanical Properties of Large Deformation High Entropy Alloy CoCrCuFeNi in Semi-solid Isothermal Heat Treatment

2020 ◽  
Vol 1 (2) ◽  
Author(s):  
Lajie WANG ◽  
Jiao XIONG ◽  
Jun LIU ◽  
X J YANG
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Cold Rolling ◽  
Liquid Fraction ◽  
Grain Morphology ◽  
High Entropy Alloy ◽  
Isothermal Heat Treatment ◽  
Scanning Calorimetry ◽  
High Entropy ◽  
Semi Solid

The semi-solid slurries of the CoCrCuFeNi high entropy alloy (HEA) were fabricated through the recrystallization and partial melting (RAP) process by cold-rolling and partial remelting. The temperature range of the semi-solid region and the relationship between the liquid fraction and the temperature were determined by the differential scanning calorimetry (DSC) curve. The effect of isothermal temperature and holding time on the evolution of the microstructure and mechanical properties of the rolled samples was analyzed. The results show that the microstructure was significantly deformed, and the tensile strength has been increased by 107% after 63% rolling deformation of the CoCrCuFeNi high entropy alloy (HEA). The high-entropy alloy after cold rolling was maintained at 1150 and 1300 ° C for 20, 30, 60, and 120 minutes respectively, the plasticity has been improved compared with the rolled high entropy alloy. The optimal plasticity was reached 13.7% and 7.9% at 1150 ℃ and 1300℃ for 30 minutes, respectively. After semi-solid isothermal heat treatment, the grain morphology changed from dendritic of as-cast or rolled to spherulite and the grain size increased significantly with time and the holding temperature increased.

scholarly journals Spinodal Decomposition and Mechanical Response of a TiZrNbTa High-Entropy Alloy

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3508 ◽  
Author(s):  
Liu ◽  
Huang ◽  
Chuang ◽  
Chou ◽  
Wei ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Spinodal Decomposition ◽  
Mechanical Response ◽  
Cast Alloy ◽  
High Entropy Alloy ◽  
Body Centered Cubic ◽  
High Entropy ◽  
Bcc Structure ◽  
20 Nm ◽  
Interconnected Structure

In this study, the effects of spinodal decomposition on the microstructures and mechanical properties of a TiZrNbTa alloy are investigated. The as-cast TiZrNbTa alloy possesses dual phases of TiZr-rich inter-dendrite (ID) and NbTa-rich dendrite (DR) domains, both of which have a body-centered cubic (BCC) structure. In the DRs of the as-cast alloy, the α and ω precipitates are found to be uniformly distributed. After homogenization at 1100 °C for 24 h followed by water quenching, spinodal decomposition occurs and an interconnected structure with a wavelength of 20 nm is formed. The α and ω precipitates remained in the structure. Such a fine spinodal structure strengthens the alloy effectively. Detailed strengthening calculations were conducted in order to estimate the strengthening contributions from the α and ω precipitates, as well as the spinodal decomposition microstructure.

scholarly journals Study of the precipitation hardening process in recycled Al-Si-Cu cast alloys

2017 ◽  
Vol 62 (1) ◽  
pp. 397-403 ◽  
Author(s):  
L. Kuchariková ◽  
E. Tillová ◽  
M. Matvija ◽  
J. Belan ◽  
M. Chalupová
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Precipitation Hardening ◽  
Cast Alloy ◽  
Solution Treatment ◽  
Second Phase ◽  
Thin Foils ◽  
Transmission Electron ◽  
Different Temperatures ◽  
Cast Alloys

AbstractThe formation of extremely small uniformly dispersed particles of a second phase within the original phase matrix during heat treatment changed material properties. Therefore the characterization of precipitation had been investigated using high resolution transmission electron microscopy (TEM) and electron diffraction of thin foils for an AlSi9Cu3 cast alloy. For investigation the hardening effect onto mechanical properties of aluminium cast was used heat treatment, which consisted from solution treatment at 515°C / 4 hours (h), followed by quenching into water with temperature 50°C and artificial aging using different temperatures 170°C and 190°C with different holding time 2, 4, 8, 16, and 32 hours. The observations of microstructure and substructure reveals that precipitation hardening has caused great changes in size, morphology and distributions of structural components, the formation of precipitates of Cu phases, and the change of mechanical properties as well.

Microstructural and Vickers Microhardness Evolution of Heat Treated Secondary Aluminium Cast Alloy

2013 ◽  
Vol 586 ◽  
pp. 137-140 ◽  
Author(s):  
Lenka Hurtalová ◽  
Eva Tillová ◽  
Mária Chalupová
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Artificial Aging ◽  
Vickers Microhardness ◽  
Cast Alloy ◽  
Solution Treatment ◽  
Holding Time ◽  
Age Hardening ◽  
Structural Components ◽  
Heat Treated

Secondary aluminium alloys are made out of aluminium scrap and aluminium-processable waste by recycling. These alloys contain different alloying elements such as Al, Cu, Fe, Si and Mg that form intermetallic phases in aluminium matrix and influence on the microstructure, basic mechanical properties and microhardness evolution in aluminium cast alloy. As experimental material was used secondary aluminium cast alloy AlSi9Cu3. Material was subjected to heat treatment (age-hardening) consisting of a solution treatment at temperature 515 °C with holding time 4 hours, than water quenching at 40 °C and artificial aging by different temperature 130 °C, 150 °C and 170 °C with different holding time (2, 4, 8, 16 and 32 hours). The age-hardening led to changes in the morphology of structural components, but also leads to precipitation of finer hardening phases in the material substructure. As optimal age-hardening mode for secondary aluminium cast alloy AlSi9Cu3 was determined mode consisting of solution treatment at temperature 515 °C with holding time 4 hours and artificial aging at temperature 170 °C with holding time 16 hours. After this heat treatment cast alloy shows the best changes in microstructure and mechanical properties. These changes are comparable with changes by primary AlSi9Cu3 cast alloy.

Effects of semi-solid extrusion and heat treatment on the microstructure, mechanics, and wear resistance of SiC/High aluminum zinc-base alloy composites

2020 ◽  
Vol 34 (25) ◽  
pp. 2050261
Author(s):  
Yingwu Wang ◽  
Xiaoqing Zuo ◽  
Songjiang Ran ◽  
Yushun Ye ◽  
Jihua Tian
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Wear Resistance ◽  
Yield Strength ◽  
Base Alloy ◽  
Extrusion Temperature ◽  
Heat Treated ◽  
Semi Solid ◽  
High Aluminum

The effects of semi-solid extrusion temperature change, extrusion pressure, SiC content and T5 heat treatment on the microstructure, mechanical properties, and wear resistance of SiC particle strengthened high aluminum zinc-base alloy [Formula: see text] composites were studied. The results show that semi-solid extrusion broke the dendrites of [Formula: see text] composites, refined their grain structure, and improved particle aggregation. The density, hardness, yield strength, tensile strength and elongation of [Formula: see text] composites first increased and then decreased when the extrusion temperature and SiC content increased, and also increased when the extrusion pressure rose. The optimal extrusion temperature, pressure and SiC content are 475[Formula: see text], 15 MPa and 10 wt.%, respectively. T5 heat treatment further refined the crystalline grains and promoted [Formula: see text] and [Formula: see text] to precipitate as strengthening phases, which improve the mechanical properties and wear resistance of [Formula: see text] composites. Consequently, the hardness, yield strength, tensile strength and elongation of the heat-treated composites improved by 18.99%, 9.66%, 4.93% and 9.76%, respectively. The wear loss of the heat-treated composites reduced by 31.65% under a load of 1600 N and a rotational speed of 200 r/min compared with the as-cast composites.

Sign in / Sign up

Export Citation Format

Share Document