High Strength Bulk Nanostructured 2219 Al Alloy Produced by High Energy Ball Milling and Hot Pressing

2008 ◽  
Vol 584-586 ◽  
pp. 97-101 ◽  
Author(s):  
T. Shanmugasundaram ◽  
V. Subramanya Sarma ◽  
B.S. Murty ◽  
Martin Heilmaier

The microstructure and mechanical properties of nano-crystalline 2219 Al alloy (Al-6.4Cu-0.29Mn, all in wt %) was studied. Nanocrystalline powders were produced from gas atomized 2219 Al alloy powders by high energy ball milling at room temperature. Powders were collected at different milling times and X-ray diffraction (XRD) analysis was used to evaluate grain size. High Vickers hardness (250HV), high compressive strength (920 MPa) and low ductility (2%) were observed in unimodal bulk nanostructured 2219 Al alloys consolidated to 99% density by hot pressing (HP). In addition, these nanocrystalline powders were blended with 15, 30 and 50% of (gas atomized) coarse-grained powders to obtain balanced mechanical properties of enhanced yield and ultimate strength and reasonable ductility and toughness as compared to either conventional or nanocrystalline 2219 alloys.

2011 ◽  
Vol 704-705 ◽  
pp. 828-831
Author(s):  
Tian Guo Wang ◽  
Qun Qin ◽  
Qiu Yue Shi ◽  
Wen Jun Zhang

TiAl-based alloy with a composition of Ti-47%Al-3%Cr (mole fraction) was prepared by high-energy ball milling and hot-pressing sintering. The relationship between microstructure and mechanical properties of Ti-47%Al-3%Cr alloy was studied by X-ray diffractometry (XRD), scanning electron microscopy (SEM) and mechanical testing. The results showed that the TiAl-based alloy with high density and uniform microstructure could be obtained by high-energy ball milling and hot-pressing sintering. The compactibility and sintering densification of the element powder could be promoted efficiently by high-energy ball milling. The main phase TiAl and few phases Ti3Al were observed in the hot pressing sintering bulk samples. In addition, the microstructure changed with ball milling times, as a result, the mechanical properties changed with the microstructure. The finer the microstructure was, the higher the strength at room temperature became. After the element powder was milled for 20 hours and hot-pressing sintered at 1300 °C for 2 hours, TiAl-based alloys were found to have good room temperature mechanical properties with the compressive strength of 2870 Mpa and the relative compressive ratio of 27.3%. Keywords: TiAl-based alloys; hot-pressing sintering; microstructure; mechanical properties


2010 ◽  
Vol 150-151 ◽  
pp. 1163-1166 ◽  
Author(s):  
Xiao Fei Wang ◽  
Xiao Lan Cai

CNT-reinforced aluminum matrix composites was produced by high-energy ball milling, the effect of rotary speed and milling time on the particle size distribution,the density and hardness of CNT-aluminum matrix composites were studied,it was observed that the rotary speed and milling time have an important effect on the mechanical properties of the CNT-aluminum matrix composites.


2010 ◽  
Vol 660-661 ◽  
pp. 82-87 ◽  
Author(s):  
Felipe Antunes Santos ◽  
Alfeu Saraiva Ramos ◽  
Claudinei dos Santos ◽  
Paulo Atsushi Suzuki ◽  
Durval Rodrigues Júnior

The present study suggests the use of high energy ball milling to mix (to dope) the phase MgB2 with the AlB2 crystalline structure compound, ZrB2, with the same C32 hexagonal structure than MgB2, in different concentrations, enabling the maintenance of the crystalline phase structures practically unaffected and the efficient mixture with the dopant. The high energy ball milling was performed with different ball-to-powder ratios. The analysis of the transformation and formation of phases was accomplished by X-ray diffractometry (XRD), using the Rietveld method, and scanning electron microscopy. As the high energy ball milling reduced the crystallinity of the milled compounds, also reducing the size of the particles, the XRD analysis were influenced, and they could be used as comparative and control method of the milling. Aiming the recovery of crystallinity, homogenization and final phase formation, heat treatments were performed, enabling that crystalline phases, changed during milling, could be obtained again in the final product.


2013 ◽  
Vol 745-746 ◽  
pp. 281-285
Author(s):  
Y.B. Yuan ◽  
Rui Xiao Zheng ◽  
Su Jing Ge ◽  
Han Yang ◽  
Chao Li Ma

Al86Ni7Y4.5Co1La1.5 (at.%) alloy powder was produced by argon gas atomization process. After high-energy ball milling, the powder was consolidated and extruded by using vacuum hot press sintering under different process conditions, sintering temperature, extrusion pressure, sintering time, etc.. The microstructure and morphology of the powder and consolidated bulk alloy were examined by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The phase transformation of the powder was investigated by differential scanning calorimetry (DSC). Mechanical properties of the consolidated bulk alloy were examined. The results showed that as the milling time increase, the volume fraction of amorphous materials and the hardness and yield strength of the bulk alloy were obvious improved.


2014 ◽  
Vol 802 ◽  
pp. 125-129
Author(s):  
Heronilton Mendes de Lira ◽  
Pilar Rey Rodriguez ◽  
Oscar Olimpio de Araújo Filho ◽  
Cezar Henrique Gonzalez ◽  
Severino Leopoldino Urtiga Filho

High performance nanostructured light metals and alloys are very interesting for replacing conventional heavier materials in many industrial components. High Energy Ball Milling and Cryomilling are useful techniques to obtain nanocrystalline powders. In this work the effect of several milling conditions such as rotation speed, time, ball to powder ratio and temperature on the crystallite and particle size and morphology in pure aluminum are presented. X-Ray Diffraction, Laser Diffraction and Scanning Electron Microscopy are used. High energy ball milling at ambient and cryogenic temperature of Al powders rapidly leads to a nanometer size down to about 35 nm. High ball to powder ratio promotes both low crystallite and particle size. Small crystallite size like 18 nm and particle size as 4 μm were achieved in the most energetic conditions at ambient temperature. Isopropyl alcohol used as liquid media and protective atmosphere has a strong influence on the results depending on the milling temperature of Al.


Sign in / Sign up

Export Citation Format

Share Document