Effects of Trace Elements on Thermal and Mechanical Properties of Al–Zn–Cu Based Alloys Using Extrusion

2020 ◽  
Vol 20 (7) ◽  
pp. 4216-4220
Author(s):  
Yong-Ho Kim ◽  
Hyo-Sang Yoo ◽  
Hyeon-Taek Son

Thermal properties and microstructure of Al-4 wt.% Zn-2 wt.% Cu–x (x = 2 wt%. Mg, 2 wt%. Sn, 0.7 wt.% Mg-0.7 wt.% Sn-0.7 wt.% Ca) alloys on cast and extrusion have been investigated with extrusion temperature of 400 °C. Al-4 wt.% Zn-2 wt.% Cu alloy was composed of Al and Al2Cu phases. By adding Mg contents, Al2Mg3Zn3 phase was increased and Al2Cu phase was decreased respectively. During hot extrusion, elongated in the extrusion direction because of severe deformation. The thermal conductivity with temperature and composition of as-extruded Al-4 wt.% Zn-2 wt.% Cu–x alloys decreases with adding 2 wt.% Mg, 2 wt.% Sn contents from 190.925 and 196.451 W/mK but thermal properties of addition of 0.7 wt.% Mg-0.7 wt.% Sn-0.7 wt.% Ca element slightly reduced from 222.32 to 180.775 W/mK. The ultimate tensile strength (UTS) for Al-4 wt.% Zn- 2 wt.% Cu alloy was 121.67 MPa. By adding 2 wt.% Mg contents, tensile strength was dramatically increased with 350.5 MPa.

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3728
Author(s):  
Gan Luo ◽  
Yujian Huang ◽  
Chengbo Li ◽  
Zhenghua Huang ◽  
Jun Du

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 %).


2016 ◽  
Vol 22 (4) ◽  
pp. 684-690
Author(s):  
Shih-Hsuan Chiu ◽  
Cheng-Lung Wu ◽  
Shun-Ying Gan ◽  
Kun-Ting Chen ◽  
Yi-Ming Wang ◽  
...  

Purpose The purpose of this study is to increase the thermal and mechanical properties of the photopolymer by filling with the copper powder for the application of rapid tooling. Design/methodology/approach In this study, the photopolymer is filled with the different loading of copper powder for investigating the thermal and mechanical properties of the copper/photopolymer composite. The thermal properties of the copper/photopolymer composite are characterized with the degradation temperature and with the thermal conductivity. The mechanical properties of copper/photopolymer composite are performed with the tensile strength and hardness testing. Moreover, the copper/photopolymer composite is imaged by using a scanning electron microscopic with energy dispersive spectroscopy. Findings The tensile strength of the copper/photopolymer composite is increased over 45 per cent at 20 phr copper loading. The hardness of the photopolymer has a negative correlation with the increasing copper loading and is decreased about 28.5 per cent at 100 phr copper loading. The degradation temperature of the copper/photopolymer composite is increased about 7.2 per cent at 70 phr copper loading. The thermal conductivity of the copper/photopolymer composite is increased over 65 per cent at 100 phr copper loading. Originality/value The photopolymer used in rapid prototyping system is generally fragile and has poor thermal properties. This study improves the thermal and mechanical properties of the photopolymer with the copper filling which has been never investigated in the field of rapid prototyping applications.


Author(s):  
Gurminder Singh ◽  
Pulak M Pandey

In the present paper, mechanical and thermal properties of rapidly manufactured copper parts were studied. The combination of three-dimensional printing and ultrasonic assisted pressureless sintering was used to fabricate copper parts. First, the ultimate tensile strength and thermal conductivity were compared between ultrasonic assisted and conventional pressureless sintered samples. The homogenously mixing of particles and local heat generation by ultrasonic vibrations promoted the sintering driving process and resulted in better mechanical and thermal properties. Furthermore, response surface methodology was adopted for the comprehensive study of the ultrasonic sintering parameters (sintering temperature, heating rate, and soaking time with ultrasonic vibrations) on ultimate tensile strength and thermal conductivity of the fabricated sample. Analysis of variance was performed to identify the significant factors and interactions. The image processing method was used to identify the surface porosity at different parameter levels to analyse the experimental results. High ultimate tensile strength was obtained at high sintering temperature, long soaking time, and slow heating rate with low surface porosity. After 60 min of soaking time, no significant effect was observed on the thermal conductivity of the fabricated sample. The significant interactions revealed less effect of soaking time at low sintering temperatures for ultimate tensile strength and less effect of heating rate at low sintering temperatures for thermal conductivity. Multi-objective optimization was carried out to identify parameters for maximum ultimate tensile strength and maximum thermal conductivity.


2013 ◽  
Vol 668 ◽  
pp. 823-829 ◽  
Author(s):  
Xiu Qing Zhang ◽  
Ge Chen ◽  
Yang Wang ◽  
Min Yu Han

Homogenized magnesium alloy Mg-6Zn-Si-0.25Ca has been hot-extruded and then aging treated for improving the magnesium alloy plastic deformation ability and promoting applications of magnesium alloys. In the hot extrusion process, the influences of extrusion parameters for microstructures and mechanical properties of Mg-6Zn-Si-0.25Ca magnesium alloy were investigated. The results show that dynamic recrystallization occurred during hot extrusion. Compared with as-cast alloy, the grains are fined remarkably, and the mechanical properties are enhanced obviously. Twin crystals appeared in grains after hot extrusion, with the extrusion temperature rising, twin crystal structures has been reduced. Aging further increased the mechanical properties of the estruded alloy. The ultimate tensile strength of Mg-6Zn-Si-0.25Ca alloy is about 385 MPa and the elongation is about 11% when extruded at 320°C(extrusion ratio is 10) and aged at 190°C for 8h.


2005 ◽  
Vol 488-489 ◽  
pp. 589-592 ◽  
Author(s):  
Ming Yi Zheng ◽  
Xiao Guang Qiao ◽  
Shi Wei Xu ◽  
Kun Wu ◽  
Shigeharu Kamado ◽  
...  

Equal channel angular extrusion (ECAE) was applied to an extruded ZW1101 (Mg - 11wt%Zn - 0.9wt%Y) Mg alloy containing quasicrystallines. The as-extruded ZW1101 alloy had an initial grain size of about 12 µm and bands of quasicrystalline phases parallel to the extrusion direction. After the extruded alloy was subjected to ECAE processing, the grain size was refined to about 0.5 µm, and the quasicrystalline phases were further broken and dispersed in the matrix. After the ECAE processing, the micro-hardness and yield strength of the alloy were increased, however, the ultimate tensile strength and the ductility of the alloy were slightly decreased.


2011 ◽  
Vol 295-297 ◽  
pp. 1718-1721
Author(s):  
Ke Liu ◽  
Jian Meng ◽  
Shu Bo Li ◽  
Chao Hui Wang

The microstructures and mechanical properties of the Mg-5Y-xMM alloys have been investigated, where MM stands for the Ce-rich misch metal. It was found that the additions of the MM led to refinement of the microstructures and improvement of the mechanical properties. The dynamic recrystallization has occurred during hot extrusion. As a result, the mechanical properties of the alloys were greatly improved after hot extrusion. It was indicated that the specimens of the extruded alloy Mg-5Y-3MM displayed a higher tensile strength, and the values of the ultimate tensile strength and yield tensile strength were 260 and 183MPa, respectively.


2013 ◽  
Vol 380-384 ◽  
pp. 4372-4375
Author(s):  
Li Zhang ◽  
Zheng Liu ◽  
Ping Li Mao

The microstructure evolution and mechanical properties of as-extruded Mg-2.5 Zn-0.5Y Mg alloy were investigated. The grainy intermetallic phases (I-phase and w-phase) observed in the as-cast Mg-2.5Zn-0.5Y alloy distributed homogeneously in the hot extruded alloys. Compared with the cast one, the extruded alloy shows predominant mechanical properties as the result of refined microstructure and the dispersed intermetallic phases formed during hot extrusion. The ultimate tensile strength and the yield tensile strength of the extruded alloy were 354.8 MPa and 305.9MPa respectively.


2018 ◽  
Vol 3 (5) ◽  
pp. 71
Author(s):  
Joseph Temitope Stephen ◽  
Adeyinka Adebayo ◽  
Gbenga Joshua Adeyemi

This paper reports the influence of solidification rate and stress-relief annealing on the mechanical properties of cast 6063 Aluminium alloy (Al6063). Ingots of Al6063 were melted and then cast using sand and metal moulds. Some of the cast samples were heat treated and then cooled in natural air. Tensile test, hardness test, impact test and microstructural analysis were carried out on the samples. The results show substantial changes in the mechanical properties of the specimens. The ultimate tensile strength, yield strength and hardness percentage elongation of cast Al6063 increases with the use of casting method with high thermal conductivity and reduces when annealing is carried out on the specimens. The ultimate tensile strength of 146.7 MPa and 163.5 MPa were recorded for sand mould and metal mould samples, respectively and the values decreases by 10.3% and 7.5% for the respective moulds. In contrast, the values of impact strength and percentage elongation of cast Al6063 rod improved with the increase in thermal conductivity of casting method and annealing operation. The ductile increased by 51.01% and 45.82% for sand mould and metal mould samples, respectively, after they were annealed. Furthermore, microstructural analysis of cast Al6063 rod revealed a fine-grained structure with increase in thermal conductivity of casting method used; however, the annealing process encouraged grain growth as a result of the stress being relieved from the samples.


Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1265 ◽  
Author(s):  
Feng Yang ◽  
Cuiqin Lan ◽  
Haiming Zhang ◽  
Jian Guan ◽  
Fan Zhang ◽  
...  

Functional fabrics have gained attention as an environmentally-friendly synthesis route. In the current study, novelty bamboo pulp fabrics with thermal conductivity properties were prepared by coating the fabric with graphene and cellulose nanocrystal (G/CNC) solutions. The influences of G and CNC concentrations on properties of fabrics were studied. The viscosities of the G/CNC solutions increased with an increase of G contents. G had an obvious thickening effect. Furthermore, compounded fabrics with different G and CNC contents (GCBPFs) were prepared and extensively characterized in terms of thermal and mechanical properties, and morphology. The ultimate thermal conductivity, bursting strength, and tensile strength of the GCBPF were 0.136 W/m·K, 1.514 MPa, and 25.8 MPa, with 4 wt.% CNC and 3 wt.% G contents, respectively. The results demonstrated that the as-fabricated GCBPFs with favorable thermal conductivity could be applied as a novel fast cooling textile for the clothing industry.


2018 ◽  
Vol 780 ◽  
pp. 93-97
Author(s):  
Walaa Abdelaziem ◽  
Atef Hamada ◽  
Mohsen Abdel-Naeim Hassan

The Simple Cyclic extrusion compression (SCEC) has been developed for producing Al-1%Cu alloys with fine microstructures and superior properties. SCEC method was applied for only two-passess.It was found that the grain structure was significantly reduced from 1500 μm to 100 μm after two passes of cyclic extrusion. The ultimate tensile strength and elongation to failure of as-cast alloy were 110 MPa and 12 %, respectively. However, the corresponding mechanical properties of the two pass CEC deformed alloy are 275 MPa and 35%, respectively. These findings ensure that a significant improvement in the grain structure has been achieved. In addition, cyclic extrusion deformation increased the surface hardness of the alloy by 50 % after two passes.


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