Effect of Ti and Zr Composite Refiner on Microstructure and Tensile Properties of Pure Aluminum

2014 ◽  
Vol 1056 ◽  
pp. 47-51
Author(s):  
Ai Wu Yu ◽  
Cheng Gang Yang ◽  
Peng He ◽  
He Chen
Keyword(s):  
Grain Size ◽  
Tensile Strength ◽  
Tensile Properties ◽  
Pure Aluminum ◽  
Grain Refining ◽  
Growth Morphology ◽  
Grain Refiner ◽  
Refining Effect ◽  
Average Grain Size ◽  
Columnar Grains

This study investigated the influence of Ti and Zr grain refiner on the microstructure and tensile properties of pure aluminum. The results show that Ti and Zr composite refiner exhibit better grain-refining effect than that of Ti or Zr added alone, only adding 0.15%Ti and 0.15%Zr can positively refine the grain size and change the growth morphology from columnar grains to fine equiaxed ones. When composite adding 0.5%Ti and 0.3%Zr, the tensile strength of the alloy is increased from 43.5MPa of pure aluminum to 84.4 MPa and the average grain size is reduced to only about 62μm.

Effect of Sc, Zr Grain Refiner on the Microstructure and Mechanical Properties of Pure Aluminum

2014 ◽  
Vol 508 ◽  
pp. 16-21 ◽  
Author(s):  
Ai Wu Yu ◽  
Cheng Gang Yang ◽  
Shang Lin Wang ◽  
Fen Cheng Liu ◽  
Qiang Zheng
Keyword(s):  
Mechanical Properties ◽  
Pure Aluminum ◽  
Eutectic Point ◽  
Strengthening Effect ◽  
Grain Refiner ◽  
Solid Solution Strengthening ◽  
Fine Grain ◽  
Microstructure And Mechanical Properties ◽  
Average Grain Size ◽  
Columnar Grains

The influence of grain refiner on the microstructure and mechanical properties of pure aluminum was investigated by separate and combined addition trace ScZr elements. The results show that the grain refinement effect of 0.2%Zr added alone is better than that of 0.2%Sc, each of them separate addition can make the strength and hardness of alloys increased obviously, and the decrease of the ductility is not remarkable, but the hardness increase of the alloy with 0.2%Sc is more significant than 0.2%Zr because of the strongly solid solution strengthening of Sc. While, the combined addition of 0.2%Sc and 0.2%Zr possesses the most excellent grain refining effect and change the growth morphology from columnar grains to equiaxed ones, the average grain size of the alloy is dropped to only about 100μm, and the strength, plastic and hardness of the alloy meet the reasonable matching, which is largely attributed to the effectively reduce of the Al-Sc eutectic point and the formation of Al3(Sc, Zr) composite particles, These Al3(Sc, Zr) particles can not only keep all the beneficial effect of A13Sc but can act as extremely effective nucleation sites of α (Al) and cause strongly fine-grain strengthening effect.

FABRICATION OF NANOSTRUCTURED TUBE BY A NOVEL SPD PROCESS: ACCUMULATIVE SPIN-BONDING (ASB)

2012 ◽  
Vol 05 ◽  
pp. 342-349
Author(s):  
M. S. MOHEBBI ◽  
A. AKBARZADEH
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Optical Microscopy ◽  
Grain Refinement ◽  
Pure Aluminum ◽  
High Strength ◽  
Commercially Pure ◽  
Tension Tests ◽  
Average Grain Size

A novel SPD process for manufacturing high strength tubes and cylinders titled as accumulative spin-bonding (ASB) is proposed. This process is applied to a commercially pure aluminum up to four cycles and its effects on the microstructure and mechanical properties are examined by optical microscopy, TEM, microhardness and tension tests. The results show that ultra-fine grains are developed during the process leading to a nanostructure with average grain size in order of 150 nm. Mechanical properties indicate that while the hardness of outer layers is more than inner ones, the hardness and its homogeneity is increased by increasing the ASB cycles. As a result of grain refinement and the scheme of hardness development, the yield and tensile strength of material are increased significantly up to the values of 194 and 235 MPa, respectively.

scholarly journals Development of Al–Mg–Si alloy performance by addition of grain refiner Al–5Ti–1B alloy

2021 ◽  
Vol 104 (2) ◽  
pp. 003685042110294
Author(s):  
Khaled Abd El-Aziz ◽  
Emad M Ahmed ◽  
Abdulaziz H Alghtani ◽  
Bassem F Felemban ◽  
Hafiz T Ali ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Corrosion Resistance ◽  
Testing Machine ◽  
Dendritic Structure ◽  
Grain Refiner ◽  
Corrosion Properties ◽  
Average Grain Size ◽  
Structural Applications ◽  
Alloy Addition

Aluminum alloys are the most essential part of all shaped castings manufactured, mainly in the automotive, food industry, and structural applications. There is little consensus as to the precise relationship between grain size after grain refinement and corrosion resistance; conflicting conclusions have been published showing that reduced grain size can decrease or increase corrosion resistance. The effect of Al–5Ti–1B grain refiner (GR alloy) with different percentages on the mechanical properties and corrosion behavior of Aluminum-magnesium-silicon alloy (Al–Mg–Si) was studied. The average grain size is determined according to the E112ASTM standard. The compressive test specimens were made as per ASTM: E8/E8M-16 standard to get their compressive properties. The bulk hardness using Vickers hardness testing machine at a load of 50 g. Electrochemical corrosion tests were carried out in 3.5 % NaCl solution using Autolab Potentiostat/Galvanostat (PGSTAT 30).The grain size of the Al–Mg–Si alloy was reduced from 82 to 46 µm by the addition of GR alloy. The morphology of α-Al dendrites changes from coarse dendritic structure to fine equiaxed grains due to the addition of GR alloy and segregation of Ti, which controls the growth of primary α-Al. In addition, the mechanical properties of the Al–Mg–Si alloy were improved by GR alloy addition. GR alloy addition to Al–Mg–Si alloy produced fine-grained structure and better hardness and compressive strength. The addition of GR alloy did not reveal any marked improvements in the corrosion properties of Al–Mg–Si alloy.

Vibratory weld conditioning during gas tungsten arc welding of al 5052 alloy on the mechanical and micro-structural behavior

2020 ◽  
Vol 17 (6) ◽  
pp. 831-836
Author(s):  
M. Vykunta Rao ◽  
Srinivasa Rao P. ◽  
B. Surendra Babu
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Welded Joints ◽  
Great Influence ◽  
Welding Process ◽  
Microstructural Characterization ◽  
Content Type ◽  
Average Grain Size

Purpose Vibratory weld conditioning parameters have a great influence on the improvement of mechanical properties of weld connections. The purpose of this paper is to understand the influence of vibratory weld conditioning on the mechanical and microstructural characterization of aluminum 5052 alloy weldments. An attempt is made to understand the effect of the vibratory tungsten inert gas (TIG) welding process parameters on the hardness, ultimate tensile strength and microstructure of Al 5052-H32 alloy weldments. Design/methodology/approach Aluminum 5052 H32 specimens are welded at different combinations of vibromotor voltage inputs and time of vibrations. Voltage input is varied from 50 to 230 V at an interval of 10 V. At each voltage input to the vibromotor, there are three levels of time of vibration, i.e. 80, 90 and 100 s. The vibratory TIG-welded specimens are tested for their mechanical and microstructural properties. Findings The results indicate that the mechanical properties of aluminum alloy weld connections improved by increasing voltage input up to 160 V. Also, it has been observed that by increasing vibromotor voltage input beyond 160 V, mechanical properties were reduced significantly. It is also found that vibration time has less influence on the mechanical properties of weld connections. Improvement in hardness and ultimate tensile strength of vibratory welded joints is 16 and 14%, respectively, when compared without vibration, i.e. normal weld conditions. Average grain size is measured as per ASTM E 112–96. Average grain size is in the case of 0, 120, 160 and 230 is 20.709, 17.99, 16.57 and 20.8086 µm, respectively. Originality/value Novel vibratory TIG welded joints are prepared. Mechanical and micro-structural properties are tested.

Effect of Li on Mechanical Properties and Electrical Conductivity of the Al–Zn–Cu–Mg Based Alloys

2021 ◽  
Vol 21 (9) ◽  
pp. 4897-4901
Author(s):  
Hyo-Sang Yoo ◽  
Yong-Ho Kim ◽  
Hyeon-Taek Son
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Grain Size ◽  
Tensile Strength ◽  
Spherical Particles ◽  
Al Alloy ◽  
High Angle ◽  
Average Grain Size ◽  
Strength Improvement ◽  
Li Content

In this study, changes in the microstructure, mechanical properties, and electrical conductivity of cast and extruded Al–Zn–Cu–Mg based alloys with the addition of Li (0, 0.5 and 1.0 wt.%) were investigated. The Al–Zn–Cu–Mg–xLi alloys were cast and homogenized at 570 °C for 4 hours. The billets were hot extruded into rod that were 12 mm in diameter with a reduction ratio of 38:1 at 550 °C. As the amount of Li added increased from 0 to 1.0 wt.%, the average grain size of the extruded Al alloy increased from 259.2 to 383.0 µm, and the high-angle grain boundaries (HGBs) fraction decreased from 64.0 to 52.1%. As the Li content increased from 0 to 1.0 wt.%, the elongation was not significantly different from 27.8 to 27.4% and the ultimate tensile strength (UTS) was improved from 146.7 to 160.6 MPa. As Li was added, spherical particles bonded to each other, forming an irregular particles. It is thought that these irregular particles contribute to the strength improvement.

scholarly journals Novel grain refinement of AZ91E magnesium alloy and the effect on hot tearing during solidfication

2021 ◽  
Author(s):  
Abdallah Elsayed
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Magnesium Alloy ◽  
Grain Refinement ◽  
Magnesium Alloys ◽  
Hot Tearing ◽  
Grain Refining ◽  
Grain Refiner ◽  
Structural Applications ◽  
Hot Tearing Susceptibility

For the A1-5Ti-1B grain refiner, the addition of 0.1 wt.% provided a 68 % reduction in grain size as compared to the unrefined AZ91E alloy at a holding time of five minutes. Grain growth restriction by TiB₂ particles was the source of grain refinement. With the addition of A1-5Ti-1B, only a small reduction in hot tearing susceptibility ws observed because large TiA1₃ particles bonded poorly with the eutectic and blocked feeding channels.The addition of 1.0 wt.% A1-1Ti-3B provided a grain size reduction of 63% as compared to the unrefined AZ91E alloy at a holding time of five minutes. The grain refinement with A1-1Ti-3B addition was attributed to a combination of TiB₂ grain growth restriction and A1B₂ nucleating sites. A significant reduction in hot tearing susceptibility was observed with A1-1Ti-3B addition as a result of a higher cooling rate and shorter local soldification time as compared to the AZ91E alloy. The reduction in hot tearing susceptibility was attributed to the good interface between eutectic and TiB₂ particles. Both grain refiners demonstrated a good resistance to fading during the holding times investigated. In addition, the AZ91E + A1-5Ti-1B and AZ91E + A1-1Ti-3B castings showed much fewer dislocation networks as compared to the untreated AZ91E casting.The development of efficient A1-Ti-B refiners can also improve castability of magnesium alloys. In addition, the fade resistant A1-Ti-B grain refiners can reduce operating costs and maintain productivity on the foundry floor. Thus, magnesium alloy with A1-Ti-B treatment have the potential for more demanding structural applications in the automobile and aerospace industries. Vehicle weight in the aerospace and automotive industries directly impacts carbon emissions and fuel efficiency. An increase in the use of lightweight materials for structural applications will result in lighter vehicles. Low density materials, such as magnesium (1.74 g/cm³) are a potential alternative to aluminium (2.70 g/cm³), to reduce component weight in structural applications.However, current magnesium alloys still do not have adequate mechanical properties and castability to meet the performance specifications of the automotive and aerospace industries. Grain refinement can significantly improve mechanical properties and reduce hot tearing during permanent mould casting. Recently, Al-Ti-B based grain refiners have shown potential in grain refining magnesium-aluminum alloys such as AZ91E. This study investigates the grain refining efficiency and fading of A1-5Ti-1B and A1-1Ti-3B in AZ91E magnesium alloy and their subsequent effect on hot tearing.The grain refiners were added at 0.1, 0.2, 0.5 and 1.0 wt.% levels. For the grain refinement and fading experiments, the castings were prepared using graphite moulds with holding times of 5, 10 and 20 minutes. For the hot tearing experiments, castings were produced representing the optimal addition level of each grain refiner. The castings were prepared using a permanent mould with pouring and mould temperatures of 720 and 180 ºC, respectively. The castings were characterized using SEM, TEM, optical microscopy and thermal analysis.

Effect of Silicon on the Microstructure, Tensile Properties and Hot Tearing Susceptibility of AZ91E Alloy

2012 ◽  
Vol 706-709 ◽  
pp. 3046-3051
Author(s):  
Comondore Ravindran ◽  
Sophie Lun Sin
Keyword(s):  
Grain Size ◽  
Tensile Strength ◽  
Tensile Properties ◽  
Room Temperature ◽  
Hot Tearing ◽  
Chinese Script ◽  
Az91 Alloy ◽  
Solidification Behavior ◽  
Last Stage ◽  
Hot Tearing Susceptibility

This Research Focused on Studying the Effect of Silicon on the Hot Tearing Susceptibility of Permanent Mould Cast AZ91E Magnesium Alloy. Varying Amounts of Silicon (0.5, 1.0 and 1.5 Wt.%) Were Added to AZ91E in the Form of an Al-53 Wt.% Si Master Alloy. the Microstructure, Grain Size and Solidification Behavior of each Alloy Were Characterized and Related to their Tensile Properties and Hot Tearing Susceptibility. the Results Showed that the Tensile Strength and the Elongation of AZ91 Alloy Decreased with the Addition of Silicon at Room Temperature, due to the Formation of Chinese Script Mg2si Particles. however, Silicon Significantly Reduced the Hot Tearing Susceptibility of AZ91E. this Was Attributed to the Reduction of the Grain Size and the Decreased Freezing Range of AZ91E, which Contributed to Improve the Interdendritic Feeding during the Last Stage of Solidification.

Influence of Isothermal Forging Temperature on Microstructure and Tensile Properties of Ti-5.8Al-4.0Sn-4.0Zr-0.7Nb-0.4Si-1.5Ta Near-α Titanium Alloy

2010 ◽  
Vol 97-101 ◽  
pp. 153-157
Author(s):  
Tao Wang ◽  
Hong Zhen Guo ◽  
Jian Hua Zhang ◽  
Ze Kun Yao
Keyword(s):  
Grain Size ◽  
Tensile Strength ◽  
Titanium Alloy ◽  
Tensile Properties ◽  
Room Temperature ◽  
Volume Fraction ◽  
Constant Strain Rate ◽  
Isothermal Forging ◽  
Α Phase ◽  
Transus Temperature

The microstructures and room temperature and 600°C tensile properties of Ti-5.8Al-4.0Sn-4.0Zr-0.7Nb -0.4Si-1.5Ta alloy after isothermal forging have been studied. The forging temperature range was from 850°C to 1075°C, and the constant strain rate of 8×10-3/S-1 was adopted. With the increase of forging temperature, the volume fraction of primary α phase decreased and the lamellar α phase became thicker when the temperatures were in range of 850°C -1040°C; The grain size became uneven and the α phase had different forms when the forging temperature was 1040°C and 1075°C respectively; The tensile strength was not sensitive to the temperature and the most difference was within 20MPa. Tensile strength and yield strength attained to the maximum when temperature was 1020°C; the ductility decreased with the increase of forging temperature, and this trend became more obvious if forging temperature was above the β-transus temperature.

scholarly journals Effect of Melt Temperature on the Effectiveness of the Grain Refining in Al-Si Castings

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
A. M. Samuel ◽  
S. S. Mohamed ◽  
H. W. Doty ◽  
S. Valtierra ◽  
F. H. Samuel
Keyword(s):  
Grain Size ◽  
Dendritic Structure ◽  
Grain Refining ◽  
Liquid Temperature ◽  
Grain Refiner ◽  
Dendrite Morphology ◽  
Melt Temperature ◽  
Strong Affinity ◽  
Rounded Form ◽  
Molten Liquid

The results inferred from the present work show that Al3Ti phase has a strong affinity to react with silicon (Si) in the molten alloy leading to formation of (Al,Si)3Ti phase instead. This reaction is independent of the grain refiner type. The molten liquid temperature would change its morphology from platelets at 750°C into dendritic structure at 950°C. It has also been observed that (Al,Si)3Ti phase platelets precipitate within the α-aluminum dendrites, whereas TiB2 or AlB2 particles are released into the surrounding interdendritic regions. Introduction of the grain refiner, regardless its type, would cause change in the α-aluminum dendrite morphology from an elongated to a more rounded form. The results also reveal that addition of 100 ppm B will reduce the initial grain size by ∼85% which is more than the effect of addition of 0.2%Ti in the form of Al-10%Ti (about 65%). Elimination of undercooling is important to obtain the maximum grain refining effect.

Research on Microstructure and Refining Effect of Al-3Ti-0.5B Master Alloy Produced with Ti Sponge

2011 ◽  
Vol 66-68 ◽  
pp. 845-849
Author(s):  
Xiao Wei Chen ◽  
Ya Gao ◽  
Hong Liang Zhao ◽  
Kang Rong Weng ◽  
Bao Feng Zhang
Keyword(s):  
Grain Size ◽  
Master Alloy ◽  
Molten Aluminum ◽  
Grain Refining ◽  
Commercial Purity ◽  
Average Grain Size ◽  
Feeding Methods ◽  
Refining Performance ◽  
Second Phases ◽  
Commercial Purity Aluminum

Al-3Ti-0.5B master alloy was prepared by reaction of Ti sponge, KBF4with aluminum melt. The morphology and distribution of the second phases effected by the feeding methods have been discussed. And the grain refining performance and the resistance to fading of the master alloy were investigated. The result shows that the Al-3Ti-0.5B master alloy which was prepared by adding mixture of Ti sponge and KBF4power into molten aluminum contains a large number of granular TiB2phase and blocky TiAl3phase. The average grain size of commercial purity aluminum was refined from 920μm to 120μm by adding 0.5wt.% of the master alloy. And the refining performance of the master alloy shows no obviously fading phenomenon when the holding time up to 30min.

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