Interface Studies of Porcelain Enamel on Aluminum

Author(s):  
D. B. Ballard ◽  
A. L. Gugeler

Aluminum and aluminum alloys can be coated with porcelain enamel slip which is fired at 1000°F for approximately 10 minutes. This produces a material with a surface layer (about 0.1 mm thick) which has the properties of porcelain and the basic mechanical properties of a light ductile metal. A problem termed spalling may arise after weathering or exposure to a corrosive salt solution, if the base metal is not chosen carefully or pretreatment of the metal is not correct. A typical failure of this type on a test panel is illustrated in Fig. 1. The spalling failure initiates at pin holes, scratches and edges, then spreads laterally by attack at the interface between the enamel and base metal. An electron fractograph at the edge of a circular spalled area on a test panel of an improperly pretreated 6061 alloy is shown in Fig. 2. The corroded metal is on the bottom and the porcelain on the top. The narrow band through the center is the fracture edge of the porcelain enamel adjacent to the interface.

2021 ◽  
Vol 892 ◽  
pp. 150-158
Author(s):  
Sugianto ◽  
Riswanda ◽  
Kadir Harlian ◽  
Akhyar Akhyar ◽  
Aminur ◽  
...  

Dissimilar weld-metal joints in aluminum alloys 5083 and 6061-T6 are often found in aircraft, railroad structures, ships, bridges, oil platforms, and building structures. However, welding of dissimilar metals is relatively more difficult due to the different metallurgy and thermophysical properties of the two alloys. The purpose of this study is to evaluate the physical-mechanical properties of the Tungsten Arc Welding (GTAW) process through numerical simulations of different welded joints between the 5083 and 6061-T6 aluminum alloys. The GTAW welding simulation process is carried out by 300 x 100 x 3 mm plate butt joints along 300 mm. GTAW weld metal is prepared for tensile test samples and metal alloy composition, the test is observed in the base metal and welded area. The results of the chemical composition test of the weld metal obtained that the composition is close to Al 5083 base metal so that the mechanical properties of the weld metal tend to be identical with Al 5083 alloy. The results of numerical simulation on the mechanical properties of GTAW weld metal at temperature conditions of 25 to 700 °C obtained several things, including 1) the range of thermal conductivity decreased from 174.393 to 86.424 W/mK. 2) The density increased from 2,348 to 2,663 gr/cm3. 3), the young modulus appears to decrease from 68,667 to 0 GPa. 4) the shear modulus decreases from 25,724 to 0 GPa. 5) the type of heat increases from 0.904 to 17,306 J/gK, and 6) the Poisson ratio increased from 0.335 to 0.5.


2011 ◽  
Vol 295-297 ◽  
pp. 751-759 ◽  
Author(s):  
Hua Shen ◽  
Wei Dong Yang ◽  
He Liang ◽  
Guang Chun Yao

The presence of Fe and harmful effects on mechanical properties of pure aluminum and aluminum alloys are introduced. Several purification methods are reviewed, but all of them are of definite limitations. It is effective that precipitation method, filtration method and centrifugal division method are integrated.


Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 875
Author(s):  
Hao Tian ◽  
Jianchao He ◽  
Jinbao Hou ◽  
Yanlong Lv

TiB crystal whiskers (TiBw) can be synthesized in situ in Ti alloy matrix through powder metallurgy for the preparation of a new type of ceramic fiber-reinforced Ti matrix composite (TMC) TiBw/Ti-6Al-4V. In the TiBw/Ti-6Al-4V TMC, the reinforced phase/matrix interface is clean and has superior comprehensive mechanical properties, but its machinability is degraded. Hence, the bonding of reliable materials is important. To further optimize the TiBw/Ti-6Al-4V brazing technology and determine the relationship between the microstructure and tensile property of the brazed joint, results demonstrate that the elements of brazing filler metal are under sufficient and uniform diffusion, the microstructure is the typical Widmanstätten structure, and fine granular compounds in β phase are observed. The average tensile strength of the brazing specimen is 998 MPa under room temperature, which is 97.3% of that of the base metal. During the high-temperature (400 °C) tensile process, a fracture occurred at the base metal of the highest tensile test specimen with strength reaching 689 MPa, and the tensile fracture involved a combination of intergranular and transgranular modes at both room temperature and 400 °C. The fracture surface has dimples, secondary cracks are generated by the fracture of TiB whiskers, and large holes form when whole TiB whiskers are removed. The proposed algorithm provides evidence for promoting the application of TiBw/Ti-6Al-4V TMCs in practical production.


Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 823
Author(s):  
Danko Ćorić ◽  
Mateja Šnajdar Musa ◽  
Matija Sakoman ◽  
Željko Alar

The development of cemented carbides nowadays is aimed at the application and sintering of ultrafine and nano-sized powders for the production of a variety of components where excellent mechanical properties and high wear resistance are required for use in high temperature and corrosive environment conditions. The most efficient way of increasing the tribological properties along with achieving high corrosion resistance is coating. Using surface processes (modification and/or coating), it is possible to form a surface layer/base material system with properties that can meet modern expectations with acceptable production costs. Three coating systems were developed on WC cemented carbides substrate with the addition of 10 wt.% Co using the plasma-assisted chemical vapor deposition (PACVD) method: single-layer TiN coating, harder multilayer gradient TiCN coating composed of TiN and TiCN layers, and the hardest multilayer TiBN coating composed of TiN and TiB2. Physical and mechanical properties of coated and uncoated samples were investigated by means of quantitative depth profile (QDP) analysis, nanoindentation, surface layer characterization (XRD analysis), and coating adhesion evaluation using the scratch test. The results confirm the possibility of obtaining nanostructured cemented carbides of homogeneous structure without structural defects such as eta phase or unbound carbon providing increase in hardness and fracture toughness. The lowest adhesion was detected for the single-layer TiN coating, while coatings with a complex architecture (TiCN, TiBN) showed improved adhesion.


Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3675
Author(s):  
A. Muthuchamy ◽  
Muthe Srikanth ◽  
Dinesh K. Agrawal ◽  
A. Raja Annamalai

In this research, we intended to examine the effect of heating mode on the densification, microstructure, mechanical properties, and corrosion resistance of sintered aluminum alloys. The compacts were sintered in conventional (radiation-heated) and microwave (2.45 GHz, multimode) sintering furnaces followed by aging. Detailed analysis of the final sintered aluminum alloys was done using optical and scanning electron microscopes. The observations revealed that the microwave sintered sample has a relatively finer microstructure compared to its conventionally sintered counterparts. The experimental results also show that microwave sintered alloy has the best mechanical properties over conventionally sintered compacts. Similarly, the microwave sintered samples showed better corrosion resistance than conventionally sintered ones.


2021 ◽  
Vol 146 ◽  
pp. 106165
Author(s):  
Muztahid Muhammad ◽  
P.D. Nezhadfar ◽  
Spencer Thompson ◽  
Ankit Saharan ◽  
Nam Phan ◽  
...  

2013 ◽  
Vol 404 ◽  
pp. 3-9 ◽  
Author(s):  
Nihat Tosun ◽  
Ihsan Dagtekin ◽  
Latif Ozler ◽  
Ahmet Deniz

Abrasive waterjet machining is one of the non-traditional methods of the recent years which found itself a wide area of application in the industry for machining of different materials. In this paper, the surface roughness of 6061-T6 and 7075-T6 aluminum alloys are being cut with abrasive waterjet is examined experimentally. The experiments were conducted with different waterjet pressures and traverse speeds. It has been found that the surface roughness obtained by cutting material with high mechanical properties is better than that of obtained by cutting material with inferior mechanical properties.


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