Effect of Milling Time and Annealing on the Mechanical Response of Mechanically Milled Aluminium

2012 ◽  
Vol 445 ◽  
pp. 815-820 ◽  
Author(s):  
Nesma T. Aboulkhair ◽  
Amal M. K. Esawi
Keyword(s):  
Milling Time ◽  
Mechanical Response ◽  
Nanostructured Material ◽  
Control Agent ◽  
Thermal Treatments ◽  
Compression Tests ◽  
Process Control Agent ◽  
Long Time ◽  
Bulk Nanostructured Material ◽  
Compressive Tests

Owing to its many exceptional properties, aluminium finds many applications in theaerospace, automotive, building and packaging industries. Enhancing its properties through alloyingor thermal treatments has been the focus of researchers’ interests for a long time. In this work, purealuminium powders were mechanically milled for up to 12 hrs and then were cold compacted andextruded to produce bulk nanostructured material. Both tensile and compressive tests wereconducted and the results compared. Post extrusion annealing treatments for up to 3 hrs wereconducted on additional samples.It was found that increasing the process control agent (PCA) content as well as the milling durationresulted in a finer microstructure and hence enhanced mechanical strength. This was accompaniedby a reduction in the ductility of the material. Moreover, compression tests revealed that thesamples are significantly more ductile in compression than in tension and that the decrease inductility with increase in milling time is less significant than in the case of tension. The differencein mechanical response is attributed to plastic instabilities. Annealing was found to enhance thetensile ductility of the samples without sacrificing strength.

scholarly journals Influence of the Oxide and Ethanol Surface Layer on Phase Transformation of Al-Based Nanocomposite Powders under High-Energy Milling

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1305 ◽  
Author(s):  
Dora Janovszky
Keyword(s):  
Particle Size ◽  
Milling Time ◽  
High Energy ◽  
Amorphous Structure ◽  
Control Agent ◽  
Dry Milling ◽  
Process Control Agent ◽  
Composite Powders ◽  
High Energy Milling ◽  
Nanocomposite Powders

Pure Al particles reinforced with amorphous-nanocrystalline Cu36Zr48Ag8Al8 particles composite powders were prepared by high-energy milling without and with ethanol. The mechanical milling procedures were compared so that in the case of dry milling the particle size increased owing to cold welding, but the crystallite size decreased below 113 nm. The amorphous phase disappeared and was not developed until 30 h of milling time. Using ethanol as a process control agent, the particle size did not increase, while the amorphous fraction increased to 15 wt.%. Ethanol decomposed to carbon dioxide, water, and ethane. Its addition was necessary to increase the amount of the amorphous structure.

scholarly journals Effects of Process Control Agent Amount, Milling Time, and Annealing Heat Treatment on the Microstructure of AlCrCuFeNi High-Entropy Alloy Synthesized through Mechanical Alloying

Metals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1493
Author(s):  
Negar Yazdani ◽  
Mohammad Toroghinejad ◽  
Ali Shabani ◽  
Pasquale Cavaliere
Keyword(s):  
Solid Solution ◽  
Process Control ◽  
Mechanical Alloying ◽  
Milling Time ◽  
Control Agent ◽  
High Entropy Alloy ◽  
Process Control Agent ◽  
Mechanically Alloyed ◽  
X Ray ◽  
High Entropy

This study was conducted to investigate the characteristics of the AlCrCuFeNi high-entropy alloy (HEA) synthesized through mechanical alloying (MA). In addition, effects of Process Control Agent (PCA) amount and milling time were investigated using X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). The results indicated that the synthesized AlCrCuFeNi alloy is a dual phase (FCC + BCC) HEA and the formation of the phases is strongly affected by the PCA amount. A high amount of PCA postponed the alloying process and prevented solid solution formation. Furthermore, with an increase in the PCA amount, lattice strain decreased, crystallite size increased, and the morphology of the mechanically alloyed particles changed from spherical to a plate-like shape. Additionally, investigation of thermal properties and annealing behavior at different temperatures revealed no phase transformation up to 400 °C; however, the amount of the phases changed. By increasing the temperature to 600 °C, a sigma phase (σ) and a B2-ordered solid solution formed; moreover, at 800 °C, the FCC phase decomposed into two different FCC phases.

Study of Milling Time and Process Control Agent on W–Mo–Cr Pre-Alloying Powders

2015 ◽  
Vol 31 (7) ◽  
pp. 926-932 ◽  
Author(s):  
Shuangji Shi ◽  
Zhuji Jin ◽  
Yan Bao ◽  
Guannan Jiang
Keyword(s):  
Process Control ◽  
Milling Time ◽  
Control Agent ◽  
Process Control Agent

Effect of process control agent on alloying and mechanical behavior of L21 phase Ni–Ti–Al alloys

2019 ◽  
Vol 740-741 ◽  
pp. 130-136 ◽  
Author(s):  
Jun Shi ◽  
Aofeng Zheng ◽  
Zehui Lin ◽  
Rong Chen ◽  
Jugong Zheng ◽  
...  
Keyword(s):  
Process Control ◽  
Mechanical Behavior ◽  
Control Agent ◽  
Al Alloys ◽  
Process Control Agent

scholarly journals Fabricación de ladrillos con polvo-residuo de mármol en México

2020 ◽  
Author(s):  
Cesar Ponce Palafox ◽  
Julián Carrillo ◽  
Areli López-Montelongo
Keyword(s):  
Management Plan ◽  
Experimental Program ◽  
Compression Tests ◽  
Seismic Demands ◽  
Load Bearing ◽  
Compression Load ◽  
Palabras Clave ◽  
Marble Powder ◽  
The Individual ◽  
Compressive Tests

Resumen La industria del mármol genera gran cantidad de desperdicio en polvo. Estos desechos carecen de un adecuado plan de manejo, además de resultar altamente contaminantes a la población que rodea el lugar de los depósitos de estos materiales. Para ofrecer una solución, en este artículo se presentan los resultados del desarrollo de un ladrillo a base del polvo de mármol. El programa experimental incluye 16 dosificaciones diferentes en las que se varía la cantidad de cemento, cal y arena, y se deja constante el polvo de mármol. El programa incluye el ensayo a compresión de 160 ladrillos, 3 ensayos a compresión en muretes, 3 pruebas de adherencia a compresión en muretes y 48 pruebas de absorción.  Los resultados de compresión y adherencia demostraron que estos ladrillos podrían ser utilizados para la construcción de muros de carga en vivienda desarrolladas en zonas de amenaza sísmica baja. Palabras clave:  Absorción; adherencia; compresión; muros de carga; vivienda   Abstract The marble industry generates large amount of dust waste. These wastes do not have a proper management plan, as well as being highly contaminating the population surrounding the site of the deposits of these materials. To offer a solution, this article shows the results of the development of a brick-based marble powder to achieve sufficient compressive strength to construction masonry walls in low-rise housing. The experimental program includes 16 different dosages that varies the amount of cement, lime, and sand, and keeping constant the marble powder. The program includes the compressive tests for 160 bricks, compressive tests for 3 small walls, validated adherence under compression tests for 3 small walls, and absorption tests for 48 bricks. The results of the test showed that the compression strength of the individual bricks and wall is 4.0 MPa y 1.9 MPa, respectively, and the absorption of the bricks es 21 %. This results of absorption , compression and adhesion are a first indication of the feasibility of used  these bricks for the construction of load-bearing walls in housing developed in areas of low seismic demands. Key Words: Absorption; adhesion; compression; load-bearing walls; housing

scholarly journals Compressive Test Characteristics and Constitutive Relationship of Wet Polypropylene Macrofiber-Reinforced Shotcrete

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Fenghui Li ◽  
Yunhai Cheng ◽  
Fei Wu ◽  
Chang Su ◽  
Gangwei Li
Keyword(s):  
Mechanical Response ◽  
Average Energy ◽  
Strain Curve ◽  
Peak Stress ◽  
Constitutive Relationship ◽  
Compression Tests ◽  
Response Characteristics ◽  
Test Characteristics ◽  
High Crack ◽  
Relationship Of

Shotcrete is often subject to poor ductility and cracking problems, particularly under high stresses. In order to deal with these issues, the feasibility of adding polypropylene macrofibers to shotcrete was verified. To ascertain the supporting effect, dry shotcrete, wet shotcrete, and wet polypropylene macrofiber-reinforced shotcrete (WPMS) were used as samples. Furthermore, the mechanical response characteristics thereof in uniaxial compression tests were compared and analyzed by acoustic emission (AE) monitoring. The results showed that the three materials were brittle, but the ductility, residual strength, and bearing capacity of polypropylene macrofiber-reinforced shotcrete were significantly enhanced. The energy absorption value of plain shotcrete was higher in the cracking stage, while that of polypropylene macrofiber-reinforced shotcrete was greater in the postpeak stage, which showed that the polypropylene macrofiber-reinforced shotcrete had the characteristics of a high crack-initiation strength and toughness. Besides, the energy release from fiber shotcrete occurred after the peak stress rather than near the peak stress. The average energy absorbed by polypropylene macrofiber-reinforced shotcrete was significantly higher than that in dry shotcrete and wet shotcrete, which implied that polypropylene macrofiber-reinforced shotcrete could mitigate the brittle instability of a shotcrete layer. A constitutive model of damage statistics was established based on the test data. The comparison between the experimental data and the fitting results can reflect the characteristics of the total stress-strain curve of such shotcrete. The results provide a basis for the optimization of polypropylene macrofiber-reinforced shotcrete layers.

scholarly journals Mechanical Response of Ni-Based CU5MCuC Alloy to Different Stabilization Thermal Treatments

2020 ◽  
Author(s):  
Andrea Gruttadauria ◽  
Silvia Barella ◽  
Claudia Fiocchi
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Mechanical Strength ◽  
Intergranular Corrosion ◽  
Mechanical Response ◽  
Annealing Treatment ◽  
Mechanical Tests ◽  
Thermal Treatments ◽  
Stabilization Treatment ◽  
Cr System

Abstract The Ni–Fe–Cr system is the basis of a series of commercial alloys featuring chemical–physical characteristics that allow them to be used in a variety of fields where excellent resistance to aggressive environments is required. In this scenario, the CU5MCuC alloy, the foundry counterpart of Alloy 825, is proving successful in the petrochemical field thanks to its good corrosion resistance in acidic and highly oxidizing environments. Intergranular corrosion resistance, critical for this material, is ensured by the stabilization treatment that allows precipitation of Nb carbides. Strengthening of this alloy takes place only via a solid solution. Therefore, its mechanical properties depend on the solution annealing treatment: often this treatment alone does not make it possible to reach the UTS imposed by the ASTM-A494 standard. In this work, the possibility of using stabilization treatment to increase mechanical strength as well was considered. Treatments, with different combinations of time and temperature, were carried out in order to modify the material’s microstructure. After the thermal treatments, microstructural analyses, mechanical tests and (pitting and intergranular) corrosion and resistance tests were carried out to identify optimal treatment parameters in order to promote the evolution of microstructural constituents capable of improving mechanical strength without decreasing corrosion resistance. The treatment that achieves the best compromise between mechanical properties and corrosion resistance is stabilization at 970 °C for 4 h.

Sign in / Sign up

Export Citation Format

Share Document