Synthesis and Performance of Nanocrystalline 5083 Aluminum Alloy Powders by Cryomilling

2009 ◽  
Vol 66 ◽  
pp. 187-190
Author(s):  
Xiu Hua Ma ◽  
Wei Min Wang ◽  
Hao Wang ◽  
Yu Cheng Wang ◽  
Zheng Yi Fu
Keyword(s):  
Aluminum Alloy ◽  
High Speed ◽  
Milling Time ◽  
Alloy Structure ◽  
Cryogenic Milling ◽  
Average Grain Size ◽  
Main Factors ◽  
And Performance ◽  
5083 Aluminum Alloy ◽  
Thermal Stability Of

In this text, 5083 aluminum alloy was prepared with the method of the liquid nitrogen cryogenic milling (cryomilling). The microstructure,microstructural evolution and thermal stability of sample powder was investigated by XRD,SEM and DSC. The experimental results show that the particles size of 5083 aluminum alloy power during cryomilling was gradually reduced; milling time and milling speed are the main factors of affected alloy structure and performance, and high speed cryomilling could result in more uniform nanometer grains. The microstructure of the cryomilling 5083 aluminum alloy for 5 hours is micron-sized agglomerates with an average grain size of 45 nm.

Influence of Work-Hardening on Wear Resistance of Machined Surface of Aviation Aluminum Alloy

2013 ◽  
Vol 589-590 ◽  
pp. 117-121 ◽  
Author(s):  
Xiu Li Fu ◽  
Zeng Hui An ◽  
Yang Qiao ◽  
Xiu Hua Men
Keyword(s):  
Wear Resistance ◽  
Aluminum Alloy ◽  
Friction Coefficient ◽  
Work Hardening ◽  
High Speed ◽  
Cutting Speed ◽  
Cutting Conditions ◽  
Micro Hardness ◽  
Machined Surface ◽  
And Performance

Work-hardening of machined surface plays an important role in the evaluation of surface quality and performance of wear resistance in the process of machining components. In this study work-hardening of machined surface during milling 7050-T7451 aluminum alloy is investigated using micro-hardness experiments under different cutting conditions. Moreover, the wear resistance of machined surface including wear quantity and friction coefficient are obtained and studied by means of high speed ring-block friction-wear tester. The work-hardening and wear resistance are particularly sensitive to cutting speed. Friction coefficient has marked drop trends and the tendency of wear quantity is ascend in first and descend at last as work-hardening increases. The comparison of wear resistance under different cutting conditions shows that the wear resistance of machined surface can be directly affected by work-hardening and machined surface obtained by high speed milling with higher micro-hardness have more superior in wear resistance performance.

The Effect of Single Pulse, Double Pulse and ForceArc MIG Welding Technology on Mechanical Properties of Welding Joint for 5083 Aluminum Alloy Used in High-Speed Train Body

2011 ◽  
Vol 337 ◽  
pp. 460-465
Author(s):  
Lei Su ◽  
Yuan Nie ◽  
Hua Ji ◽  
Chuan Ping Ma ◽  
Shao Hua Yan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
High Speed ◽  
Single Pulse ◽  
Double Pulse ◽  
High Speed Train ◽  
Welding Joint ◽  
5083 Aluminum Alloy ◽  
Very High

The technology of lightening manufacture for aluminum alloy train body is one key of manufacturing high-speed train . The train body is a whole bearing loading tubular structure which is welded together by the large, hollow, thin-walled aluminum extrusion. Therefore，the demand for welding quality of aluminum alloy train body is very high，and the mechanical properties of joints severely affected the overall strength of welded components. To solve this problem ,we use the 421 EXPERT forceArc MIG of PHOENIX series of German EWM company to perform three types of experiments of single pulse, double pulse, and forceArc welding ,and then effect of three welding methods on mechanical properties of Welding joint for 5083 aluminum alloy used in high-speed train body is compared.

Synthesis and Characterization of Nanocrystalline M50 Steel Powders by Cryomilling

1995 ◽  
Vol 400 ◽  
Author(s):  
M. L. Lau ◽  
B. Huang ◽  
R. J. Perez ◽  
S. R. Nutt ◽  
E. J. Lavernia
Keyword(s):  
High Speed ◽  
High Speed Steel ◽  
High Energy ◽  
Average Grain Size ◽  
Energy Ball ◽  
Nanocrystalline Microstructure ◽  
Al Powder ◽  
Thermal Stability Of ◽  
M50 Steel

AbstractThe present study investigated the synthesis of nanocrystalline high speed steel M50 (4.5% Mo, 4.0% Cr, 1.0% V, 0.8% C, balance Fe) by cryogenic high energy ball milling (cryomilling). Pre-alloyed M50 steel was spray atomized, and subsequently cryomilled in liquid nitrogen for 25 hours. Elemental Al powder was added prior to cryomilling in order to promote the formation of nanoscale Al2O3 and AlN particles, which improved the thermal stability of the nanocrystalline M50 steel. Following annealing at 1373 K, the M50 steel was found to retain its nanocrystalline microstructure with the average grain size of 40–80 nm.

scholarly journals Design Evaluation and Performance Analysis of the Inside-Filling Air-Assisted High-Speed Precision Maize Seed-Metering Device

2021 ◽  
Vol 13 (10) ◽  
pp. 5483
Author(s):  
Jinwu Wang ◽  
Xin Qi ◽  
Changsu Xu ◽  
Ziming Wang ◽  
Yeming Jiang ◽  
...  
Keyword(s):  
High Speed ◽  
Parametric Design ◽  
Optimized Design ◽  
Maize Seed ◽  
Working Pressure ◽  
Factors Affecting ◽  
Poor Seed ◽  
Main Factors ◽  
And Performance ◽  
Seed Metering Device

In view of the problems of a poor seed-filling state and poor seed-cleaning effect of a precision metering device under high-speed working conditions, an inside-filling air-assisted high-speed precision maize seed-metering device was designed, fabricated, and evaluated. The overall structure and working principles of the seed-metering device are explained. Theoretical analysis and parametric design of the key parts, such as the horizontal stirring notch seed-metering plate and the wheel seed-cleaning mechanism, were carried out. The main factors that produce multiple seeding problems were studied. The forward speed (FS) and working pressure (WP) of the seed-metering device are determined as the main factors affecting the seeding performance. A quadratic orthogonal rotation combination experiment was designed. The relationship between influencing factors and performance indexes was constructed using the Design-Expert 10.0.7 software. The response surface method was used to optimize the experimental results. The results of the bench validation experiments showed that the seeding performance of the seed-metering device was excellent when the FS of the seed-metering device was 13.10 km/h and the WP of the seed-metering device was 4.75 kPa. The results of the bench comparison showed that the seeding performance of the designed seed-metering device was better than that of the conventional air-suction precision seed-metering device. This study provides theoretical and practical references for the optimized design of a pneumatic precision seed-metering device and the sustainable development of grain.

Inline Rolling of 5182 Aluminum Alloy Strip Cast by a Vertical Type High Speed Twin Roll Caster

2010 ◽  
Vol 139-141 ◽  
pp. 477-480
Author(s):  
Ryoji Nakamura ◽  
Shuya Hanada ◽  
Shinji Kumai ◽  
Hisaki Watari
Keyword(s):  
Aluminum Alloy ◽  
High Speed ◽  
Rolling Speed ◽  
Center Line ◽  
Alloy Strip ◽  
Ripple Mark ◽  
Roll Casting ◽  
Strip Cast ◽  
Twin Roll Caster ◽  
Twin Roll

An inline hot rolling was operated on 5182 aluminum alloy strip cast using a vertical type high speed caster (VHSTRC) at the speed of 60 m/min. A porosity existing at center line of the thickness and a ripple mark on the surface, these are typical defects of the strip cast by the VHSTRC, could be improved by the inline rolling. The rolling speed was as same as the roll-casting-speed of 60m/min. The temperature of the strip, when the inline rolling was operated, was 450oC. The reduction of the strip of the inline rolling was 35%.

scholarly journals Spatially Resolved Experimental Modal Analysis on High-Speed Composite Rotors Using a Non-Contact, Non-Rotating Sensor

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4705
Author(s):  
Julian Lich ◽  
Tino Wollmann ◽  
Angelos Filippatos ◽  
Maik Gude ◽  
Juergen Czarske ◽  
...  
Keyword(s):  
High Speed ◽  
Natural Frequencies ◽  
Mode Shapes ◽  
Fiber Reinforced ◽  
Structural Dynamic ◽  
Spatially Resolved ◽  
Glass Fiber Reinforced ◽  
Vibration Responses ◽  
And Performance

Due to their lightweight properties, fiber-reinforced composites are well suited for large and fast rotating structures, such as fan blades in turbomachines. To investigate rotor safety and performance, in situ measurements of the structural dynamic behaviour must be performed during rotating conditions. An approach to measuring spatially resolved vibration responses of a rotating structure with a non-contact, non-rotating sensor is investigated here. The resulting spectra can be assigned to specific locations on the structure and have similar properties to the spectra measured with co-rotating sensors, such as strain gauges. The sampling frequency is increased by performing consecutive measurements with a constant excitation function and varying time delays. The method allows for a paradigm shift to unambiguous identification of natural frequencies and mode shapes with arbitrary rotor shapes and excitation functions without the need for co-rotating sensors. Deflection measurements on a glass fiber-reinforced polymer disk were performed with a diffraction grating-based sensor system at 40 measurement points with an uncertainty below 15 μrad and a commercial triangulation sensor at 200 measurement points at surface speeds up to 300 m/s. A rotation-induced increase of two natural frequencies was measured, and their mode shapes were derived at the corresponding rotational speeds. A strain gauge was used for validation.

scholarly journals A Physical-Based Plane Stress Constitutive Model for High Strength AA7075 under Hot Forming Conditions

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 314
Author(s):  
Fulong Chen ◽  
Haitao Qu ◽  
Wei Wu ◽  
Jing-Hua Zheng ◽  
Shuguang Qu ◽  
...  
Keyword(s):  
Grain Size ◽  
Aluminum Alloy ◽  
Plane Stress ◽  
Metal Forming ◽  
Electron Backscatter Diffraction ◽  
High Strength ◽  
Material Model ◽  
Hot Forming ◽  
Industrial Processing ◽  
Average Grain Size

Physicallybased constitutive equations are increasingly used for finite element simulations of metal forming processes due to the robust capability of modelling of underlying microstructure evolutions. However, one of thelimitations of current models is the lack of practical validation using real microstructure data due to the difficulties in achieving statistically meaningful data at a sufficiently large microstructure scale. Particularly, dislocation density and grain size governing the hardening in sheet deformation are of vital importance and need to be precisely quantified. In this paper, a set of dislocation mechanics-based plane stress material model is constructed for hot forming aluminum alloy. This material model is applied to high strength 7075 aluminum alloy for the prediction of the flow behaviorsconditioned at 300–400 °C with various strain rates. Additionally, an electron backscatter diffraction (EBSD) technique was applied to examine the average grain size and geometrical necessary dislocation (GND) density evolutions, enabling both macro- and micro- characteristics to be successfully predicted. In addition, to simulate the experienced plane stress states in sheet metal forming, the calibrated model is further extended to a plane stress stateto accuratelypredict the forming limits under hot conditions.The comprehensively calibrated material model could be used for guidinga better selection of industrial processing parameters and designing process windows, taking into account both the formed shape as well as post formed microstructure and, hence, properties.

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