Figure 2 - available via license: Creative Commons Attribution 4.0 International
Content may be subject to copyright.
Source publication
Al-0.9Si-0.6Mg (wt%) alloy conductive wires were designed and produced by continuous rheo-extrusion process. The effects of different heat treatment on microstructure, mechanical and conductive properties of the wires were studied. Results show that, after T6 heat treatment, conductive property of the alloy increased while elongation decreased with...
Context in source publication
Similar publications
The reasons of destruction of archaeological fi nds from iron alloys, the mechanism of formation of oxohydroxides on a surface of iron objects are analyzed. Applied ways of stabilization of archeological iron are resulted. The temperature range of destruction of akageneit structure is taken at heat treatment on air. The opportunity of stabilization...
![Fig. 2.1: Cross section view of a scale [5]](profile/Krystof_Mraz/publication/353923620/figure/fig1/AS:1057343097806853@1629101647824/Cross-section-view-of-a-scale-5_Q320.jpg)
![Fig. 2.3: Growth of individual oxide types [8]](profile/Krystof_Mraz/publication/353923620/figure/fig3/AS:1057343102017536@1629101648075/Growth-of-individual-oxide-types-8_Q320.jpg)
![Fig. 2.4: Thermal conductivity of dense oxides [12]](profile/Krystof_Mraz/publication/353923620/figure/fig4/AS:1057343102001152@1629101648310/Thermal-conductivity-of-dense-oxides-12_Q320.jpg)
![Fig. 2.5: Thermal conductivity of porous scale [15]](profile/Krystof_Mraz/publication/353923620/figure/fig5/AS:1057343102013450@1629101648502/Thermal-conductivity-of-porous-scale-15_Q320.jpg)
The scale layer, consisting of porous iron oxides, formed on the steel surface during the
heat treatment has a great impact on thermal metallurgical processes. The thermal conductivity of a scale is one of the key parameters for the numerical modeling of the steel cooling and descaling. However, the conductivity is highly influenced by the scale
po...
In the present work the corrosion behavior of both aircraft aluminum alloy 2024 and 6061 were studied by cyclic polarization test in Rainwater, before and after heat treatment at room temperature (25 °C). The corrosion resistance of both alloys decreases after these alloys were solution treatment at a temperature of 495 °C for 2hr for AA2024 alloy...
Most failures in steel materials are due to fatigue damage, so it is of great significance to analyze the key features of fatigue strength (FS) in order to improve fatigue performance. This study collected data on the fatigue strength of steel materials and established a predictive model for FS based on machine learning (ML). Three feature-construc...
The production of aluminothermic alloys is accompanied by high temperatures of the reaction products, the control of which is difficult both by direct and indirect methods. Filling the metal into the mould without controlling the casting temperature provides a high gradient between the metal and the mould, which leads to the formation of quenching...
Citations
... According to Figure 7, it is worth noting that the conductivity performance of different states for Al-2Fe-xCo alloys are in the following sequence: as-cast < annealing < rolling. It is known that many factors affect the thermal conductivity of alloys, such as alloy composition [2,7,36,37], heat treatment [10,11,38,39], melt treatment [40,41], plastic deformation [1,42], and so on. In our study, compared with the as-cast samples, the thermal conductivities of alloys significantly increase after annealing treatment due to the evolution of the morphology and elimination of lattice defects. ...
The microstructures, mechanical properties, and thermal conductivity (TC) of Al-2Fe-xCo (x = 0~0.8) alloys in as-cast, homogeneous annealed, and cool rolled states are systematically studied. Results indicate that appropriate Co modification (x ≤ 0.5) simultaneously improves the thermal and mechanical properties of as-cast Al-2Fe alloys. The improvement of TC is attributed to ameliorating the morphology of primary Al3Fe phases from needles to short rods and fine particles, which decreases the scattering probability of free electrons during the electronic transmission. However, further increasing the Co content (x = 0.8) decreases the TC due to the formation of a coarse plate-like Al2FeCo phase. Besides, the thermal conductivity of annealed Al-2Fe-xCo alloys is higher than that of as-cast alloys because of the elimination of lattice defects and spheroidization of Al3Fe phases. After cool rolling with 80 % deformation, thermal conductivity of alloys slightly increases due to the breaking down of Al2FeCo phases. The rolled Al-2Fe-0.3Co alloy exhibits the highest thermal conductivity, which is about 225 W/(m·K), approximately 11 % higher than the as-cast Al-2Fe sample. The ultimate tensile strength (UTS) and elongation (EL) of as-cast Al-2Fe-0.5Co (UTS: 138 MPa; EL: 22.0 %) are increased by 35 % and 69 %, respectively, compared with those of unmodified alloy (UTS: 102 MPa; EL: 13.0 %).
... Although many efforts have been made to enhance the mechanical performance of B 4 C composites, the fabrication methods still need to improve to establish solid bonding between B 4 C particles and aluminum matrix. Compared with traditional processing methods, semisolid slurring and rheological forming method can effective homogenize the microstructure by reducing dendrites [24]. Grains could be fully refined and spheroidized during the process while agglomeration is also reduced. ...
To reveal the formation and wear mechanisms of rheo-formed aluminum alloy - B 4 C composites, A356 alloy − 10 mass% B 4 C composite material was fabricated by semi-solid stirring rheo-casting and rolling process. The presence of Al 3 BC was confirmed by XRD analysis and hinted that chemical bonding formed at interfaces between aluminum matrix and B 4 C particles. Tensile test results demonstrated that addition of B 4 C facilitated improving the tensile strength by refining matrix and providing particle strengthening. Failure tests revealed that the failure type of the composite transferred from interfacial debonding to particle cracking with increasing wear load. The wear rate of the composite was approximately 48% lower than that of aluminum alloy under 60 N load. The friction coefficient of the composite under 60 N load also significantly decreased due to formation of B 2 O 3 and H 3 BO 3 as solid lubricants.
... The melt was purged at 710 • C and poured into a continuous rheo-extrusion (CRE) equipment developed by Guan et al. at 730 • C to prepare Al-Sc-Zr-Fe alloy wire with the diameter of 10 mm [15]. Part of the alloy wires were subjected to a solid solution treatment (SST) at 630 • C for 21 h, and then followed by an artificial aging treatment (solution treatment followed by aging treatment (SAT)) at 300 • C for 24 h. ...
... The melt was purged at 710 °C and poured into a continuous rheo-extrusion (CRE) equipment developed by Guan et al. at 730 °C to prepare Al-Sc-Zr-Fe alloy wire with the diameter of 10 mm [15]. Part of the alloy wires were subjected to a solid solution treatment (SST) at 630 °C for 21 h, and then followed by an artificial aging treatment (solution treatment followed by aging treatment (SAT)) at 300 °C for 24 h. ...
Low-cost heat-resistant Al-Sc-Zr-Fe conductor wires were successfully manufactured by continuous rheo-extrusion process, and the mechanical and conductive properties of the materials were analyzed and compared after three different thermo-mechanical treatment methods. The coarse plate-shape Al3Fe phase transformed to small sized rod-like phase after solid solution treatment at 630 °C for 21 h. Direct aging treatment at 300 °C for 24 h led to the refinement and spheroidization of Al3Fe phase with a diameter of 200 nm. After the subsequent aging treatment at 300 °C for 24 h, the tensile strength and conductivity of the alloy wire significantly increased due to the homogeneous precipitation of the coherent spherical Al3(Sc, Zr) phase with an average size of 15 nm. The tensile strength, elongation, and conductivity of the alloy conductor wire after optimized thermo-mechanical treatment reached 165.7 MPa, 7.3%, and 60.26% International Annealed Copper Standard (IACS), respectively. The thermal resistance of the present alloy wire was superior to that of standard AT1 type alloy conductor according to IEC international standard.
... Micro-cracks or other disintegrations were not observed on the surface or in the sub-surface layer. This is attributed to proper preparation of the samples using heat treatment [27] in combination with favorable electric and heat conductivities (G = 1.54 S¨m´1¨mm´2; λ t = 30 W¨m´1¨K´1) of the applied steel EN X210Cr12. Figure 2 shows allocation of particular sub-surface layers of untreated eroded sample surface observed by the digital microscope Keyence VK-X150 (Keyence International, Mechelen, Belgium) at 1000ˆmagnification where structural changes occur in the terms that represent technological parameters setting for roughing operations. ...
... Micro-cracks or other disintegrations were not observed on the surface or in the sub-surface layer. This is attributed to proper preparation of the samples using heat treatment [27] in combination with favorable electric and heat conductivities (G = 1.54 S•m −1 •mm −2 ; λt = 30 W•m −1 •K −1 ) of the applied steel EN X210Cr12. Figure 2 shows allocation of particular sub-surface layers of untreated eroded sample surface observed by the digital microscope Keyence VK-X150 (Keyence International, Mechelen, Belgium) at 1000× magnification where structural changes occur in the terms that represent technological parameters setting for roughing operations. ...
This paper describes results of experimental research on the thin microhardened surface layer of a machined surface that occurs in materials using wire electrical discharge machining (WEDM) with brass wire electrode. The direct influence of microhardened surface layer on resulting machined surface quality of tool steel EN X210Cr12 (W.-Nr. 1.2080) was examined. The aim of the experiment was to contribute to the knowledge of mutual interactions between main WEDM technological parameters, the influence of these parameters on the total affected depth, and on the variation of microhardness of sub-surface layers of machined surface. Based on the microhardness experimental measurements, mathematical models were established by the Least Square Method (LSM) in order to simulate and predict final quality of machined surface after WEDM. Recommendations are given for setting the main technological parameters of the discharge process concerning minimization of total microhardened surface layer depth and microhardened surface layer homogeneity along the whole cross-section profile of the machined surface.
... New processes are also entering the manufacturing scene affording new possibilities to create novel microstructures and thereby also new types of property combinations [6,7]. The introduction of new processes also shifts the boundary between processes that used to be made in fully solid state and now move towards casting and more liquid processing resulting in hybrid processes [6][7][8]. Independent of this, post treatment processes for bulk and surface properties are still needed to be used together with the novel processing property capability [8,9]. Last but not least, it is also critical to understand the application in which the part is to be used and its implications for the stability of its properties [10]. ...
... The introduction of new processes also shifts the boundary between processes that used to be made in fully solid state and now move towards casting and more liquid processing resulting in hybrid processes [6][7][8]. Independent of this, post treatment processes for bulk and surface properties are still needed to be used together with the novel processing property capability [8,9]. Last but not least, it is also critical to understand the application in which the part is to be used and its implications for the stability of its properties [10]. ...
Castings and the cast metals are among the most important facets creating a foundation for modern life. [...]
An as-cast Mg–6Zn–0.9Zr–0.9Nd (mass%) alloy was isothermally heat treated to form semi-solid microstructure, and its corrosion behaviors before and after heat treatment were revealed. During the isothermal heat treatment, the microstructure transformed into homogenous spheroidized structure, and the liquid phase presented network-shaped morphology. The electrochemical results showed that there is no passivation behavior and obvious local corrosion in the semi-solid formed alloy, and homogeneous general corrosion is the primary corrosion form. The network-shaped liquid phase prevented the flow of corrosion media between solid phases, and therefore inhibited the formation of pitting corrosion.
Fullsize Image
In the present work, the electrical resistivity, thermal conductivity and microstructure of the 70 at. % Al-15 at. % Sn-15 at. % Zn alloy have been investigated. The electrical resistivity of the alloy was obtained by four-point probe (DC 4PPT) method. Electrical resistivity measurements are used in conjunction with Wiedeman-Franz (W-F) law and Smith-Palmer (S-P) equations to obtain the thermal conductivity of the alloy. The microstructure parameters of the Al-Sn-Zn ternary alloy were obtained by XRD. The surface and phases of alloy were showed by SEM, MAPPING and the composition of each phase was determined by EDX.
