Mechanical and Fatigue Properties of Tungsten Heavy Alloy Prepared by RF-Plasma

2021 ◽  
Author(s):  
Ondřej KovářÍk ◽  
Jaroslav Čech ◽  
Jan Cizek ◽  
Jakub Klečka ◽  
Michal Hajíček
Keyword(s):  
Mechanical Properties ◽  
Crack Growth ◽  
Heavy Alloy ◽  
Fatigue Properties ◽  
Protective Atmosphere ◽  
Rf Plasma ◽  
Tungsten Heavy Alloy ◽  
Threshold Region ◽  
Early Results ◽  
Near Threshold

Abstract Tungsten heavy alloy (WHA) of W-Ni composition was deposited from a blend of standard thermal spray powders using radio frequency inductively coupled plasma torch (RF-ICP) in a protective atmosphere. The deposit (RF WHA) contained a fully developed WHA structure; i.e.; spherical W particles embedded in a Ni-rich matrix. The bending tensile strength Rm; bending yield strength Rp;0.2; and elastic modulus of the deposit were compared with two W-Ni-Co references fabricated by powder metallurgy (PM WHA) via sintered and quenched (PMSQ); and forged and annealed (PM-FA). While the RF deposit properties are comparable with the PM-SQ reference; the PMFA exhibited higher mechanical properties. The deposit showed very limited ductility A < 3%. The fatigue crack growth rate in the deposit measured in bending (R < -1) was comparable to the PM-SQ reference material in the near-threshold region whereas the forged PM-FA had significantly better fatigue performance. In the near-threshold fatigue regime; the crack growth took place in the Ni-rich matrix. In the Paris regime; the similar fracture mode was observed; with the exception of PM-SQ; where the tungsten particles fracture contributed significantly. The static failure was exclusively trans-particle in RF WHA; while both PM WHAs failed by a mix of ductile matrix failure and trans-particle cleavage fracture. The fracture toughness of the deposit was significantly lower than the references. These early results indicate that RF-plasma spray is a suitable and efficient manufacturing method for production of WHA materials; however with limited mechanical properties in some aspects.

Microstructure and mechanical properties of a rotary friction welded tungsten heavy alloy

2019 ◽  
Vol 61 (3) ◽  
pp. 209-212
Author(s):  
Ramachandran Damodaram ◽  
Gangaraju Manogna Karthik ◽  
Sree Vardhan Lalam
Keyword(s):  
Mechanical Properties ◽  
Heavy Alloy ◽  
Tungsten Heavy Alloy ◽  
Microstructure And Mechanical Properties

scholarly journals Affecting Structure Characteristics of Rotary Swaged Tungsten Heavy Alloy Via Variable Deformation Temperature

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4200 ◽  
Author(s):  
Adéla Macháčková ◽  
Ludmila Krátká ◽  
Rudolf Petrmichl ◽  
Lenka Kunčická ◽  
Radim Kocich
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Deformation Behaviour ◽  
Heavy Alloy ◽  
Tungsten Heavy Alloy ◽  
Structural Development ◽  
Material Behaviour ◽  
Real Experiment ◽  
Structure Characteristics ◽  
Rotary Swaging

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).

scholarly journals The Influence of Cyclic Sintering on the Structure and Mechanical Properties of Tungsten Heavy Alloy

2016 ◽  
Vol 16 (4) ◽  
pp. 131-136 ◽  
Author(s):  
P. Skoczylas ◽  
M. Kaczorowski
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Main Part ◽  
Hydrogen Atmosphere ◽  
Liquid Phase Sintering ◽  
Heavy Alloy ◽  
Tungsten Heavy Alloy ◽  
Structure Investigations ◽  
Scanning Electron ◽  
Mechanical Studies

Abstract The results of structure and mechanical properties investigations of tungsten heavy alloy (THA) after cyclic sintering are presented. The material for study was prepared using liquid phase sintering of mixed and compacted powders in hydrogen atmosphere. The specimens in shape of rods were subjected to different number of sintering cycles according to the heating schemes given in the main part of the paper From the specimens the samples for mechanical testing and structure investigations were prepared. It follows from the results of the mechanical studies, that increasing of sintering cycles lead to decrease of tensile strength and elongation of THA with either small or no influence on yield strength. In opposite to that, the microstructure observations showed that the size of tungsten grain increases with number of sintering cycles. Moreover, scanning electron microscope (SEM) observations revealed distinctly more trans-granular cleavage mode of fracture in specimens subjected to large number of sintering cycles compared with that after one or two cycles only.

STUDY ON THE RELATION BETWEEN MECHANICAL AND BALLISTIC PROPERTIES OF SOME CERAMICS

2008 ◽  
Vol 22 (09n11) ◽  
pp. 1201-1208 ◽  
Author(s):  
CHEOL SOO KIM ◽  
CHANG WOOK KIM
Keyword(s):  
Mechanical Properties ◽  
Kinetic Energy ◽  
Flexural Strength ◽  
Density Ratio ◽  
Shaped Charge ◽  
Heavy Alloy ◽  
Tungsten Heavy Alloy ◽  
Engineering Ceramics ◽  
Ballistic Properties ◽  
Long Rod

In this study, we analyzed the relation between mechanical and ballistic properties of several engineering ceramics that were expected to be used as armor materials. After the measurements of mechanical properties (Young's modulus, density, hardness, flexural strength and toughness), we measured the ballistic properties against a long rod KE projectile ( L / D =10.7, Kinetic Energy, tungsten heavy alloy) and copper jet projectile (40mm shaped charge warhead). The ballistic properties were generally increased as the increasing ratio of mechanical properties and density. As the HEL/density ratio was increased, it especially appeared that the ballistic properties were lineally increased.

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