Effects of Consolidation Process on the Microstructure and Mechanical Properties of ODS Ferritic Alloy

2013 ◽  
Vol 747-748 ◽  
pp. 507-512 ◽  
Author(s):  
Tong Liu ◽  
Hai Long Shen ◽  
Tong Wen Zhang ◽  
Mu Zhu ◽  
Cheng Gong Qin

The oxide-dispersion-strengthened (ODS) ferritic alloy powders (Fe-14Cr-3Al-2W-0.1Ti-0.35Y2O3) were prepared by mechanical alloying (MA) at a rotation speed of 720 rpm for 24 h. All the elements were mixed homogenously in the powder, and Cr and Al dissolved in α-Fe after MA. The bulk samples were produced by spark plasma sintering (SPS) at 950 and 50 MPa and by hot isostatic pressing (HIP) at 1150 and 130 MPa, respectively. The SPS sample showed a tensile strength of 730 MPa and a poor ductility due to the existence of pores in microsize. The HIP sample had a high tensile strength of 980 MPa, yield strength of 710 MPa and elongation of 10.3 %. The excellent mechanical properties of the HIP sample was due to the small grain size of the matrix of about 400 nm and the fine oxide particles of 5-40 nm.

2020 ◽  
Vol 10 ◽  
pp. 19-27
Author(s):  
O. A. Bazyleva ◽  
◽  
I. Yu. Efimochkin ◽  
E. G. Arginbaeva ◽  
R. S. Kuptsov ◽  
...  

The technology of obtaining of composite material experimental samples based on VKNA type an intermetallic alloy reinforced with oxide particles in an amount of 2 – 5 vol. % is presented. Anintermetallic VKNA-1V alloycontaining the 80 – 90 mas. % of γ′-phase was used as the matrix prototype. Al2O3 particles, as well as complex oxides Al2O3·Y2O3, Al2O3·Y2O3·HfO2, were used as reinforcing particles. Granules of VKNA-1V alloy were obtained by gas atomization at the Hermiga Gas Atomiser. Subsequently, these granules were subjected to mechanical alloying with the aim of introducing particles of the above mentioned oxides compositions to form a composite mixture corresponding in composition to the aimed composite material. Experimental composite material samples with different reinforcing particles contents were obtained from powder mixtures by spark plasma sintering (SPS) with further hot isostatic pressing (HIP). To study the microstructure of experimental samples the method of scanning electron microscopy was used. Time to failure of experimental samples sintered by spark plasma combined with HIP was determined at a temperature of 900 °С and stress of 50 MPa; 45 MPa and 35 MPa. It is shown that to determine the application areas of the developed composition, the hot isostatic pressing operation is necessary, but not sufficient.


Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 548 ◽  
Author(s):  
Leonid Agureev ◽  
Valeriy Kostikov ◽  
Zhanna Eremeeva ◽  
Svetlana Savushkina ◽  
Boris Ivanov ◽  
...  

The article presents the study of alumina nanoparticles’ (nanofibers) concentration effect on the strength properties of pure nickel. The samples were obtained by spark plasma sintering of previously mechanically activated metal powders. The dependence of the grain size and the relative density of compacts on the number of nanofibers was investigated. It was found that with an increase in the concentration of nanofibers, the average size of the matrix particles decreased. The effects of the nanoparticle concentration (0.01–0.1 wt.%) on the elastic modulus and tensile strength were determined for materials at 25 °C, 400 °C, and 750 °C. It was shown that with an increase in the concentration of nanofibers, a 10–40% increase in the elastic modulus and ultimate tensile strength occurred. A comparison of the mechanical properties of nickel in a wide range of temperatures, obtained in this work with materials made by various technologies, is carried out. A description of nanofibers’ mechanisms of influence on the structure and mechanical properties of nickel is given. The possible impact of impurity phases on the properties of nickel is estimated. The tendency of changes in the mechanical properties of nickel, depending on the concentration of nanofibers, is shown.


2019 ◽  
Vol 38 (2019) ◽  
pp. 404-410 ◽  
Author(s):  
Weijuan Li ◽  
Haijian Xu ◽  
Xiaochun Sha ◽  
Jingsong Meng ◽  
Zhaodong Wang

AbstractIn this study, oxide dispersion strengthened (ODS) ferritic steels with nominal composition of Fe–14Cr–2W–0.35Y2O3 (14Cr non Zr-ODS) and Fe–14Cr–2W–0.3Zr–0.35Y2O3 (14Cr–Zr-ODS) were fabricated by mechanical alloying (MA) and hot isostatic pressing (HIP) technique to explore the impact of Zr addition on the microstructure and mechanical properties of 14Cr-ODS steels. Microstructure characterization revealed that Zr addition led to the formation of finer oxides, which was identified as Y4Zr3O12, with denser dispersion in the matrix. The ultimate tensile strength (UTS) of the non Zr-ODS steel is about 1201 MPa, but UTS of the Zr-ODS steel increases to1372 MPa, indicating the enhancement of mechanical properties by Zr addition.


2014 ◽  
Vol 1040 ◽  
pp. 772-777 ◽  
Author(s):  
Lilia I. Shevtsova ◽  
Michail A. Korchagin ◽  
Alexander Thömmes ◽  
Vyacheslav I. Mali ◽  
Alexander G. Anisimov ◽  
...  

In this paper structure and mechanical properties of Ni3Al intermetallic compound was studied. The materials was fabricated according to different schemes, which combined mechanical alloying of Ni and Al powders, self-propagating high temperature synthesis (SHS) and spark plasma sintering (SPS). Relative density of all sintered samples was ~ 97 %. Microhardness of the sintered materials ranged from 6100 to 6300 MPa. SPS of 86.71 % wt. Ni and 13.29 % wt. Ni powder at 1100 °C led to formation of material with the highest level of tensile strength equal to 400 MPa.


2007 ◽  
Vol 534-536 ◽  
pp. 833-836 ◽  
Author(s):  
J.K. Lee ◽  
Taek Soo Kim ◽  
Ha Guk Jeong ◽  
Jung Chan Bae

The microstructure and mechanical properties of the Mg97Zn1Y2 alloy prepared by spark plasma sintering of gas atomized powders have been investigated. After consolidation, precipitates were observed to form in the α-Mg solid solution matrix of the Mg97Zn1Y2 alloy. These precipitates consisted of Mg12YZn and Mg24Y5 phases. The density of the consolidated bulk Mg-Zn-Y alloy was 1.86 g/cm3. The ultimate tensile strength and elongation were dependent on the consolidation temperature, which were in the ranges of 280 to 293 MPa and 8.5 to 20.8 %, respectively.


Author(s):  
Zheng-Yang Hu ◽  
Hai-Chun Peng ◽  
Zhao-Hui Zhang ◽  
Peng Song ◽  
Ming Chen ◽  
...  

Abstract A hybrid of TiB whiskers and TiC particles reinforced TC4 matrix composites were in-situ synthesized by spark plasma sintering (SPS) using a TC4-0.6wt.% B4C powder mixture at temperatures range from 550°C to 1150°C. The effect of sintering temperature on microstructure, grain size, mechanical properties and densification process of the (TiB+TiC)/ TC4 matrix composites were investigated. The composite sintered at 1050℃ has the highest tensile strength (1129.0 MPa), yield strength (1077.8MPa) and plasticity (7.1%). The aspect ratio of TiB whiskers increases almost linearly below 1050°C and its highest value is 33.2. The grain size of TiC increases with the increase of sintering temperature, and rapid growth occurs in the range of 850°C to 950°C. The composite sintered body appears four shrinkage stages before applying sintering pressure. The corresponding peak temperatures are 663℃, 758℃, 840℃ and 994℃, respectively.


2014 ◽  
Vol 682 ◽  
pp. 188-191 ◽  
Author(s):  
Lilia I. Shevtsova ◽  
T.S. Sameyshcheva ◽  
D.D. Munkueva

The structure and mechanical properties of materials fabricated by spark plasma sintering of mechanically activated mixture of nickel and aluminum nanopowders were investigated. On account of the elemental powders ratio formation of Ni3Al compound was expected. Relative density of sintered samples was equal to ~ 95 %, microhardness of materials was 6540 MPa. Ultimate tensile strength of samples tested according to three-point bending scheme exceed 1100 MPa.


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