Strain hardening and failure of powder metallurgy iron

1984 ◽  
Vol 23 (10) ◽  
pp. 805-809 ◽  
Author(s):  
A. S. Drachinskii ◽  
A. E. Kushchevskii ◽  
Yu. N. Podrezov ◽  
S. A. Firstov
Keyword(s):  
Powder Metallurgy ◽  
Strain Hardening ◽  
Metallurgy Iron

Sulfide Transformation from Self-Lubricating to Free-Cutting in Powder Metallurgy Iron-Based Alloys

2020 ◽  
Vol 29 (2) ◽  
pp. 1034-1042
Author(s):  
Fang Yang ◽  
Qian Qin ◽  
Haixia Sun ◽  
Peng Liu ◽  
Zhimeng Guo
Keyword(s):  
Powder Metallurgy ◽  
Iron Based ◽  
Metallurgy Iron

Strain hardening and fracture of VT6 alloy synthesized by the method of powder metallurgy

2008 ◽  
Vol 44 (3) ◽  
pp. 429-434 ◽  
Author(s):  
O. I. Dekhtyar ◽  
M. V. Matviichuk ◽  
I. V. Moiseeva ◽  
D. H. Savvakin
Keyword(s):  
Powder Metallurgy ◽  
Strain Hardening

Effect of carbon content on instantaneous strain-hardening behaviour of powder metallurgy steels

2008 ◽  
Vol 497 (1-2) ◽  
pp. 505-511 ◽  
Author(s):  
R. Narayanasamy ◽  
V. Anandakrishnan ◽  
K.S. Pandey
Keyword(s):  
Powder Metallurgy ◽  
Carbon Content ◽  
Strain Hardening ◽  
Instantaneous Strain

Efficient and green treatment of ultrapure magnetite to prepare powder metallurgy iron powders

2021 ◽  
Vol 378 ◽  
pp. 19-28
Author(s):  
Zhengqi Guo ◽  
Deqing Zhu ◽  
Jian Pan ◽  
Congcong Yang ◽  
Siwei Li ◽  
...  
Keyword(s):  
Powder Metallurgy ◽  
Iron Powders ◽  
Metallurgy Iron

Hardening by Crystallization During Superplastic Flow in a Powder-metallurgy-processed Zr65Al10Ni10Cu15 Glass Metallic Alloy

2005 ◽  
Vol 20 (6) ◽  
pp. 1447-1455 ◽  
Author(s):  
H.G. Jeong ◽  
W.J. Kim
Keyword(s):  
Powder Metallurgy ◽  
Strain Rate ◽  
Strain Hardening ◽  
Tensile Elongation ◽  
Metallic Alloy ◽  
Powder Metallurgy Method ◽  
Testing Time ◽  
Liquid Region ◽  
Strain Rates ◽  
Strain And Strain Rate

The superplastic behavior of the Zr65Al10Ni10Cu15 glass metallic alloy produced by the powder metallurgy method was examined in the supercooled liquid region. A tensile elongation as large as 750% was obtained at 6.3 × 10−3 s−1 at 697 K. Large strain hardening took place during the course of deformation and systematic trend was observed in the hardening behavior. Plots of stress versus strain and strain rate versus stress at 697 K showed that Newtonian viscous flow governed the plastic flow until the onset of strain hardening. Microstructure and differential scanning calorimetry analyses as well as flow stress versus testing time curves provided consistent evidence that the strain hardening was induced by crystallization. Crystallization was enhanced in the gauge region (deformed region) as compared to the grip region (undeformed region). Crystallization is expected to decrease tensile ductility by decreasing the strain-rate-sensitivity value and increasing the degree of brittleness. Hardening by crystallization, however, can contribute to neck stability if crystallization is enhanced in the neck region. The strain hardening and plastic stability parameters were measured as a function of strain for different strain rates at 696 K. The strain hardening parameter remained highly positive until failure. Because of this, the neck stability parameter (I) could be I < 0 in the entire hardening region. The contribution of hardening by crystallization to neck stability was found to be much more significant than that by grain growth in the superplastic metallic alloys. Reducing the specimen heating-and-holding time was suggested to promote superplasticity deformation without delaying initiation of crystallization. The largest tensile strain in the hardening region where crystallization may be obtained at the strain rates and temperatures where crystallization rate is controlled to be the lowest while maintaining I ≤ 0 throughout deformation.

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