scholarly journals A Two-phase Constitutive Model with Damage for Tungsten Heavy Alloy

2021 ◽  
Vol 15 (2) ◽  
pp. 211-234
Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1660
Author(s):  
Senthilnathan Natarajan ◽  
Venkatachalam Gopalan ◽  
Raja Annamalai Arunjunai Rajan ◽  
Chun-Ping Jen

Tungsten heavy alloys are two-phase metal matrix composites that include W–Ni–Fe and W–Ni–Cu. The significant feature of these alloys is their ability to acquire both strength and ductility. In order to improve the mechanical properties of the basic alloy and to limit or avoid the need for post-processing techniques, other elements are doped with the alloy and performance studies are carried out. This work focuses on the developments through the years in improving the performance of the classical tungsten heavy alloy of W–Ni–Fe through doping of other elements. The influence of the percentage addition of rare earth elements of yttrium, lanthanum, and their oxides and refractory metals such as rhenium, tantalum, and molybdenum on the mechanical properties of the heavy alloy is critically analyzed. Based on the microstructural and property evaluation, the effects of adding the elements at various proportions are discussed. The addition of molybdenum and rhenium to the heavy alloy gives good strength and ductility. The oxides of yttrium, when added in a small quantity, help to reduce the tungsten’s grain size and obtain good tensile and compressive strengths at high temperatures.


2019 ◽  
Vol 61 (3) ◽  
pp. 209-212
Author(s):  
Ramachandran Damodaram ◽  
Gangaraju Manogna Karthik ◽  
Sree Vardhan Lalam

2021 ◽  
Author(s):  
Yuxin Xu ◽  
Xiaoming Qiu ◽  
Jinlong Su ◽  
Suyu Wang ◽  
Xiaohui Zhao ◽  
...  

2011 ◽  
Vol 341-342 ◽  
pp. 432-435
Author(s):  
Wei Huang ◽  
Ya Feng Li ◽  
Kai Wen Tian ◽  
Fu Jun Shang ◽  
Yong Liu ◽  
...  

The failure mechanism of tungsten matrix composite was studied with microscale numerical simulation. The results show that high strength tungsten particles are the real loading elements of composite, its strength level embodies the whole property of the composite to some extent. The real stress in tungsten particles is much higher than the external load, so failure may take place when the external load is less than the theoretical strength of tungsten particles.


Author(s):  
Xiuwen Lai ◽  
Zhanjiang Wang ◽  
Na Qin

The plastic behaviors’ description of a tungsten heavy alloy (95W-3.5Ni-1.5Fe) at temperatures of 298–773 K and strain rates of 0.001–11,000 s−1 is systematically studied based on four constitutive models, that is, Zerilli-Armstrong model, modified Zerilli-Armstrong model, Mechanical Threshold Stress model, and modified Mechanical Threshold Stress model. The quasi-static compression experiments using an electronic universal testing machine and the dynamic compression experiments using a split Hopkinson pressure bar apparatus are employed to obtain the true stress–strain curves at a total of three temperatures (298 K, 573 K, and 773 K) and a wide range of strain rates (0.001–11,000 s−1). The parameters of the four constitutive models are obtained by the above fundamental experimental data and Grey Wolf Optimizer. The correlation coefficient and average absolute relative error are used to evaluate the predicted performance of these models. Modified Mechanical Threshold Stress model is found to have the highest predicted performance in describing the flow stress of the 95W-3.5Ni-1.5Fe alloy. Eventually, two compression experiments whose loading conditions are not in the fundamental experiments are conducted to validate the four models.


2019 ◽  
Vol 8 (2) ◽  
pp. 2209-2215
Author(s):  
Mai Essam ◽  
Ayman Elsayed ◽  
Ahmed Shash ◽  
Mahmoud Adly

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4200 ◽  
Author(s):  
Adéla Macháčková ◽  
Ludmila Krátká ◽  
Rudolf Petrmichl ◽  
Lenka Kunčická ◽  
Radim Kocich

This study focuses on numerical prediction and experimental investigation of deformation behaviour of a tungsten heavy alloy prepared via powder metallurgy and subsequent cold (20 °C) and warm (900 °C) rotary swaging. Special emphasis was placed on the prediction of the effects of the applied induction heating. As shown by the results, the predicted material behaviour was in good correlation with the real experiment. The differences in the plastic flow during cold and warm swaging imparted differences in structural development and the occurrence of residual stress. Both the swaged pieces exhibited the presence of residual stress in the peripheries of W agglomerates. However, the NiCO matrix of the warm-swaged piece also exhibited the presence of residual stress, and it also featured regions with increased W content. Testing of mechanical properties revealed the ultimate tensile strength of the swaged pieces to be approximately twice as high as of the sintered piece (860 MPa compared to 1650 MPa and 1828 MPa after warm and cold swaging, respectively).


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