Comparative Study of Surface Contaminated Layer on Titanium Aluminum Alloy and Titanium Alloy Investment Castings

2021 ◽  
Vol 1035 ◽  
pp. 602-607
Author(s):  
Zhi Hua Feng ◽  
Xian Fei Ding ◽  
Xin Feng ◽  
Hai Nan ◽  
Ai Bin Zhang
Keyword(s):  
Titanium Alloy ◽  
Aluminum Alloy ◽  
Comparative Study ◽  
Chemical Reaction ◽  
Microhardness Measurement ◽  
Ceramic Mold ◽  
Al Alloy ◽  
Ti Alloy ◽  
Titanium Aluminum ◽  
Alloy Castings

A comparative study of the surface contaminated layer formed by chemical reaction between ceramic-mold and titanium aluminum alloy castings or titanium alloy castings were carried out. The morphology, thickness and hardness of the surface contaminated layer were characterized by means of metalloscopy and microhardness measurement. The results show that surface contaminated layers formed between Ti-Al alloy castings and ceramic-mold, also formed between Ti alloy castings and ceramic-mold. The surface contaminated layers of Ti-Al alloy castings were continuous and compact, their thickness was about 0~90 μm. The surface contaminated layers of titanium alloy castings were not even, their thickness was 0~900 μm. Titanium alloy is more liable to react with the ceramic -mold than the Ti-Al alloy.

Diffusion in the Interface Region of Ti/TiAl-Nb Bonding

2006 ◽  
Vol 249 ◽  
pp. 193-200
Author(s):  
Lembit A. Kommel
Keyword(s):  
Titanium Alloy ◽  
Transition Zone ◽  
Chemical Elements ◽  
Titanium Content ◽  
Interface Region ◽  
Diffusion Region ◽  
Ti Alloy ◽  
Titanium Aluminum Alloys ◽  
Titanium Aluminum ◽  
Solid Titanium

Diffusion in the interface regions of lightweight heatproof quality titanium and titanium/aluminum alloys was investigated. We studied the diffusion of aluminum from intermetallide to titanium alloy. The concentration of other chemical elements and microhardness has been measured in diffusion region formed in the solid titanium alloy. The interface region includes a transition zone from the initially solid Ti-alloy and the molten TiAl-Nb intermetallic substrate. The width of the interface region after diffusion bonding is 45-60 µm. The titanium content decreases and aluminum content increases starting from surface up to 120-150 µm in depth in solid titanium alloy. As a result of diffusion, the intermetallic Ti3Al thin layer was formed in the transition zone in the Ti-alloy substrate. The microporosity was also formed in the interface region.

Defects in Aluminum Alloy Castings

2019 ◽  
Author(s):  
John Campbell
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Hydrogen Embrittlement ◽  
Stress Corrosion Cracking ◽  
Tensile Elongation ◽  
Shrinkage Porosity ◽  
Corrosion Cracking ◽  
The Other ◽  
Al Alloy ◽  
Alloy Castings

Most of the major defects in Al alloy castings are the result of entrainment processes. The entrainment of the surface of the liquid creates bifilm defects, and the entrainment of air creates bubbles and bubble trails. Occasionally the entrainment of foreign inclusions, such as sand inclusions, can also be a problem. Bifilms form the initiators of gas porosity, shrinkage porosity, hot tears, and cracks. Since bifilms can be controlled by improved melting and casting techniques, all these defects are controllable. In addition, bifilms control the mechanical properties of castings, particularly tensile elongation, toughness, and fatigue. The other important effects caused by bifilms such as invasive corrosion behavior including pitting, stress corrosion cracking, and possibly hydrogen embrittlement, are beyond the scope of this review.

Counter-Gravity Casting Equipment and Technologies for Thin-Walled Al-Alloy Parts in Resin Sand Molds

2009 ◽  
Vol 618-619 ◽  
pp. 585-589 ◽  
Author(s):  
Wan Qi Jie ◽  
Xin Lei Li ◽  
Qi Tang Hao
Keyword(s):  
Aluminum Alloy ◽  
Hold Time ◽  
Al Alloy ◽  
Filling Rate ◽  
Gravity Casting ◽  
Gravity Condition ◽  
Large Size ◽  
Thin Walled ◽  
Alloy Castings ◽  
Sensitive Pressure

A counter-gravity casting equipment (CGCE) has been developed, which is specially designed for the production of large-size thin-walled high-quality aluminum alloy parts with resin sand molds. In this equipment, molten metal will be pushed upward counter-gravity into the mold at predetermined rate by compressed air, and solidified at an increased pressure. The equipment uses assembled valve system developed ourselves, and has sensitive pressure-adjusting property. All of the casting parameters, including filling rate, pressure-exerting sequence, pressure hold time etc., can be closely controlled by a self-designed computer program. Up to 2 ton casting can be produced with the equipment. Compared to the castings produced under conventional gravity conditions, the castings under counter-gravity condition have generally high soundness, higher tensile strengths and ductility. The pinhole defects are also degraded obviously. The equipment and the technology have been widely adopted by several users in China for the production of large-size thin-walled aluminum alloy castings with high property requirements.

Friction Stir Welding of Aluminum Alloy 1100 and Titanium-Al Alloy

2016 ◽  
Author(s):  
B. K. Dhindaw ◽  
P. S. De ◽  
Priyadarshini Jayashree
Keyword(s):  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
High Speed ◽  
High Speed Steel ◽  
Al Alloy ◽  
Ti Alloy ◽  
Joint Region ◽  
Friction Stir ◽  
Shoulder Region ◽  
Material Mixing

A intercalating joint between Al and Ti alloy is friction stir welded using a high speed steel tool. The material mixing occurs mainly in the shoulder region while the pin region shows nominal mixing. Microscopy and hardness experiments indicate sporadic formation of intermetallic compounds. The joint region near the shoulder and to some extent below it shows increase in hardness compared to the base Ti alloy.

Corrosion inhibition characteristics of multilayer Si-DLC, phosphating and anodizing coatings deposited on 2024 Al alloy: A comparative study

2021 ◽  
Vol 117 ◽  
pp. 108460
Author(s):  
Saad M. Fayed ◽  
Peng Gao ◽  
Dongxu Chen ◽  
Shengli Li ◽  
Yanwen Zhou ◽  
...  
Keyword(s):  
Comparative Study ◽  
Corrosion Inhibition ◽  
Al Alloy

Gold Nanoparticle-Enhanced Laser-Induced Breakdown Spectroscopy and Three-Dimensional Contour Imaging of an Aluminum Alloy

2020 ◽  
pp. 000370282097304
Author(s):  
Amal A. Khedr ◽  
Mahmoud A. Sliem ◽  
Mohamed Abdel-Harith
Keyword(s):  
Gold Nanoparticles ◽  
Aluminum Alloy ◽  
Three Dimensional ◽  
Plasma Temperature ◽  
Spectral Lines ◽  
Laser Induced Breakdown Spectroscopy ◽  
Al Alloy ◽  
Boltzmann Plot ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown

In the present work, nanoparticle-enhanced laser-induced breakdown spectroscopy was used to analyze an aluminum alloy. Although LIBS has numerous advantages, it suffers from low sensitivity and low detection limits compared to other spectrochemical analytical methods. However, using gold nanoparticles helps to overcome such drawbacks and enhances the LIBS sensitivity in analyzing aluminum alloy in the current work. Aluminum was the major element in the analyzed samples (99.9%), while magnesium (Mg) was the minor element (0.1%). The spread of gold nanoparticles onto the Al alloy and using a laser with different pulse energies were exploited to enhance the Al alloy spectral lines. The results showed that Au NPs successfully improved the alloy spectral lines intensity by eight times, which could be useful for detecting many trace elements in higher matrix alloys. Under the assumption of local thermodynamic equilibrium, the Boltzmann plot was used to calculate the plasma temperature. Besides, the electron density was calculated using Mg and H lines at Mg(I) at 285.2 nm and Hα(I) at 656.2 nm, respectively. Three-dimensional contour mapping and color fill images contributed to understanding the behavior of the involved effects.

Comparative study on two compressing methods of clinched joints with dissimilar aluminum alloy sheets

2017 ◽  
Vol 93 (5-8) ◽  
pp. 1929-1937 ◽  
Author(s):  
Chao Chen ◽  
Xiaolan Han ◽  
Shengdun Zhao ◽  
Fan Xu ◽  
Xuzhe Zhao ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Comparative Study

Hole Expansion by Using Al-Alloy Specimen and 0.45% Carbon Steel Specimen

2010 ◽  
Vol 452-453 ◽  
pp. 601-604
Author(s):  
Muhammed Sohel Rana ◽  
Md. Shafiul Ferdous ◽  
Chobin Makabe ◽  
Masaki Fujikawa
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Life ◽  
Carbon Steel ◽  
Cold Work ◽  
Fatigue Crack Initiation ◽  
Steel Specimen ◽  
Expansion Method ◽  
Al Alloy ◽  
2024 Aluminum Alloy ◽  
Cold Worked

The enhancement method of fatigue life and the crack initiate and growth behavior of a holed specimen was investigated by using the 2024 Aluminum alloy and 0.45% Carbon steel. The purpose of present study is to propose a simple technical method for enhancement of fatigue life in a notched specimen. Also, the effect of local plastic deformation by cold work on fatigue crack initiation behavior was examined. This paper presents a basic experimental kinematic cold expansion method by inserting and removing a pin through the specimen hole. The shape of cross-section of pin was a circle or an ellipse. It was shown that the fatigue life of the specimen with the cold-worked hole was longer than that of the specimen with non-cold-worked hole for the case of same stress level in aluminum alloy and carbon steel. Also, the fatigue strength was higher in the case of the cold expanded hole. In this study, a methodology of lengthening of fatigue life of holed specimen is shown. Also, the improvement conditions of fatigue life were significantly affected by shape of pin, local hardening and residual stress conditions. The fatigue life improvement of the damaged component of structures was studied.

The permeability of Lost Foam pattern coatings for Al alloy castings

2008 ◽  
Vol 43 (16) ◽  
pp. 5441-5447 ◽  
Author(s):  
W. D. Griffiths ◽  
P. J. Davies
Keyword(s):  
Al Alloy ◽  
Alloy Castings ◽  
Foam Pattern ◽  
Lost Foam
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