scholarly journals Effect of Transition Metals Oxides on the Physical and Mechanical Properties of Sintered Tungsten Heavy Alloys

Crystals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 825
Author(s):  
Ayman H. Elsayed ◽  
Mohamed A. Sayed ◽  
Osama M. Dawood ◽  
Walid M. Daoush
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Electrode Materials ◽  
Electrical Discharge Machining ◽  
Electrical Contact ◽  
Transition Element ◽  
Physical And Mechanical Properties ◽  
Tungsten Heavy Alloy ◽  
Heavy Alloys ◽  
Tungsten Heavy Alloys

The addition of transition element oxides to tungsten heavy alloys (WHAs) fabricated by powder metallurgy technique provides new materials with higher density and electrical conductivity, which may be adequate in some applications such as kinetic energy penetrators. Additionally, materials with higher electrical conductivity are required for electrical contact applications such as electrical discharge machining (EDM) electrode materials. WHAs were fabricated by compacting its mixed constituents followed by sintering. Ni, Co and Fe are used as binding phases of the tungsten particles and oxides of Zr, Ti and Y are used as oxide dispersing strengthening (ODS) agents of the sintered materials. The results show that all of the chosen factors (i.e., pressure of compaction process, temperature of sintering, type of binding material and type of oxide) have clear effects on all properties of ODS tungsten heavy alloy specimens. The density and electrical conductivity increase with the increase in sintering temperature. Hardness and compression strength were also measured to evaluate the mechanical properties of sintered samples.

scholarly journals Correlating Microstrain and Activated Slip Systems with Mechanical Properties within Rotary Swaged WNiCo Pseudoalloy

Materials ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 208 ◽  
Author(s):  
Pavel Strunz ◽  
Lenka Kunčická ◽  
Přemysl Beran ◽  
Radim Kocich ◽  
Charles Hervoches
Keyword(s):  
Mechanical Properties ◽  
Thermomechanical Processing ◽  
Radiation Shielding ◽  
Tungsten Heavy Alloy ◽  
Slip Systems ◽  
Soft Matrix ◽  
Heavy Alloys ◽  
Dislocation Densities ◽  
Tungsten Heavy Alloys ◽  
Edge Dislocations

Due to their superb mechanical properties and high specific mass, tungsten heavy alloys are used in demanding applications, such as kinetic penetrators, gyroscope rotors, or radiation shielding. However, their structure, consisting of hard tungsten particles embedded in a soft matrix, makes the deformation processing a challenging task. This study focused on the characterization of deformation behavior during thermomechanical processing of a WNiCo tungsten heavy alloy (THA) via the method of rotary swaging at various temperatures. Emphasis is given to microstrain development and determination of the activated slip systems and dislocation density via neutron diffraction. The analyses showed that the grains of the NiCo2W matrix refined significantly after the deformation treatments. The microstrain was higher in the cold swaged sample (44.2 × 10−4). Both the samples swaged at 20 °C and 900 °C exhibited the activation of edge dislocations with <111> {110} or <110> {111} slip systems, and/or screw dislocations with <110> slip system in the NiCo2W matrix. Dislocation densities were determined and the results were correlated with the final mechanical properties of the swaged bars.

Enhancement of Physical and Mechanical Properties of Oxide Dispersion-Strengthened Tungsten Heavy Alloys

2016 ◽  
Vol 47 (5) ◽  
pp. 2387-2395 ◽  
Author(s):  
Walid Mohamed Rashad Daoush ◽  
Ayman Hamada Abdelhady Elsayed ◽  
Omayma Abdel Gawad El Kady ◽  
Mohamed Abdallah Sayed ◽  
Osama Monier Dawood
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Oxide Dispersion Strengthened ◽  
Oxide Dispersion ◽  
Heavy Alloys ◽  
Tungsten Heavy Alloys

scholarly journals Influence of Pulse Current Forward-Reverse Duty Cycle on Structure and Performance of Electroplated W–Cu Composite Coatings

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1233
Author(s):  
Yuchao Zhao ◽  
Nan Ye ◽  
Haiou Zhuo ◽  
Chaolong Wei ◽  
Weiwei Zhou ◽  
...  
Keyword(s):  
Composite Coating ◽  
Duty Cycle ◽  
Electrode Materials ◽  
Pulse Current ◽  
Electrical Discharge Machining ◽  
Composite Coatings ◽  
Electrical Contact ◽  
Pulse Plating ◽  
Fusion Welding ◽  
Raw Material

Tungsten-copper (W–Cu) composites are widely used as electrical contact materials, resistance welding, electrical discharge machining (EDM), and plasma electrode materials due to their excellent arc erosion resistance, fusion welding resistance, high strength, and superior hardness. However, the traditional preparation methods pay little attention to the compactness and microstructural uniformity of W–Cu composites. Herein, W–Cu composite coatings are prepared by pulse electroplating using nano-W powder as raw material and the influence of forward-reverse duty cycle of pulse current on the structure and mechanical properties is systematically investigated. Moreover, the densification mechanism of the W–Cu composite coating is analyzed from the viewpoints of forward-pulse plating and reverse-pulse plating. At the current density (J) of 2 A/dm2, frequency (f) of 1500 Hz, forward duty cycle (df) of 40% and reverse duty cycle (dr) of 10%, the W–Cu composite coating rendered a uniform microstructure and compact structure, resulting in a hardness of 127 HV and electrical conductivity of 53.7 MS/m.

Refractory metal alloying: A new method for improving mechanical properties of tungsten heavy alloys

2017 ◽  
Vol 709 ◽  
pp. 609-619 ◽  
Author(s):  
U. Ravi Kiran ◽  
A. Panchal ◽  
M. Prem Kumar ◽  
M. Sankaranarayana ◽  
G.V.S. Nageswara Rao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Refractory Metal ◽  
New Method ◽  
Heavy Alloys ◽  
Tungsten Heavy Alloys

Study on Microstructure and Properties of Aged Cu-Ti-Zr-RE Alloy

2009 ◽  
Vol 79-82 ◽  
pp. 1687-1690
Author(s):  
Xing Min Cao ◽  
Yu Bin Zhu ◽  
Fuan Guo ◽  
Chao Jian Xiang
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Electrical Conductivity ◽  
Plastic Deformation ◽  
Tensile Strength ◽  
Physical And Mechanical Properties ◽  
Good Combination ◽  
Maximum Strength ◽  
Micro Hardness ◽  
Peak Aging

Electrical conductivity, tensile strength and micro-hardness of Cu-3.5wt.%Ti-0.1wt.%Zr-RE alloy were investigated after optimizing technics of plastic deformation and the heat treatment. The results show that good combination of the physical and mechanical properties, such as tensile strength 1160 MPa, micro-hardness 335 Hv and electrical conductivity 15 IACS% can be obtained on peak aging at 420°C for 7 h. Maximum strength was associated with the precipitation of metastable, ordered and coherent β/ (Cu4Ti) phase on peak aging. Then the strength decreased due to the precipitation of β (Cu3Ti) phase in alloys overaged.

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