scholarly journals Mechanical Milling-Assisted Spark Plasma Sintering of Fine-Grained W-Ni-Mn Alloy

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1323 ◽  
Author(s):  
Yanlin Pan ◽  
Daoping Xiang ◽  
Ning Wang ◽  
Hui Li ◽  
Zhishuai Fan
Keyword(s):  
Spark Plasma Sintering ◽  
Mechanical Milling ◽  
Bending Strength ◽  
Sintering Temperature ◽  
Interface Fracture ◽  
Composite Powders ◽  
Fine Grained ◽  
Plasma Sintering ◽  
Binding Phase ◽  
Spark Plasma

Fine-grained W-6Ni-4Mn alloys were fabricated by spark plasma sintering (SPS) using mechanical milling W, Ni and Mn composite powders. The relative density of W-6Ni-4Mn alloy increases from 71.56% to 99.60% when it is sintered at a low temperature range of 1000–1200 °C for 3 min. The spark plasma sintering process of the alloy can be divided into three stages, which clarify the densification process of powder compacts. As the sintering temperature increases, the average W grain size increases but remains at less than 7 µm and the distribution of the binding phase is uniform. Transmission electron microscopy (TEM) observation reveals that the W-6Ni-4Mn alloy consists of the tungsten phase and the γ-(Ni, Mn, W) binding phase. As the sintering temperature increases, the Rockwell hardness and bending strength of alloys initially increases and then decreases. The optimum comprehensive hardness and bending strength of the alloy are obtained at 1150 °C. The main fracture mode of the alloys is W/W interface fracture.

The Cu Matrix Strengthened by TiH2–C In-Situ Synthesized via Mechanical Milling and Spark Plasma Sintering

2021 ◽  
Vol 21 (4) ◽  
pp. 2687-2691
Author(s):  
Nguyen Thi ◽  
Hoang Oanh ◽  
Nguyen Hoang Viet
Keyword(s):  
Spark Plasma Sintering ◽  
Mechanical Milling ◽  
Sintering Temperature ◽  
Annealing Treatment ◽  
High Energy ◽  
Composite Powders ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Tic Nanoparticles

The present work is focused on the fabrication and the investigation of microstructures of copperbased TiC nanocomposites produced by mechanical milling in a high energy planetary ball mill. TiH2, carbon and copper powders were used as starting materials in which In-Situ reaction between carbon and TiH2 occurs to form TiC nanoparticles. The mixture powders of Cu–TiH2–C were milled for 12 h at 450 rpm in Argon gas. Annealing treatment process at 950 °C for 2 h was applied for as-milled composite powders to enhance In-Situ reaction. The consolidation of composite powders was conducted by spark plasma sintering under uniaxial pressing of 70 MPa. Sintering procedure was done at 950 and 1000 °C for 5 min. The results indicated that as TiC nanoparticles are formed after sintering at 950 °C and the TiC particles are increased up at higher sintering temperature of 1000 °C. Fracture surface of sintered samples shows ductile mode. HR-TEM image showed the crystal size of copper was about 10 nm for sample sintered at 1000 °C. The hardness and relative density of the nanocomposites increase when increasing sintering temperature.

Effect of Spark Plasma Sintering on the Microstructure Evolution and Properties of M3:2 High-Speed Steel

2014 ◽  
Vol 788 ◽  
pp. 329-333
Author(s):  
Rui Zhou ◽  
Xiao Gang Diao ◽  
Jun Chen ◽  
Xiao Nan Du ◽  
Guo Ding Yuan ◽  
...  
Keyword(s):  
Powder Metallurgy ◽  
Spark Plasma Sintering ◽  
High Speed ◽  
Bending Strength ◽  
Sintering Temperature ◽  
High Speed Steel ◽  
Continuous Heating ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
The Impact

Effects of sintering temperatures on the microstructure and mechanical performance of SPS M3:2 high speed steel prepared by spark plasma sintering was studied. High speed steel sintering curve of continuous heating from ambient temperature to 1200°C was estimated to analyze the sintering processes and sintering temperature range. The sintering temperature within this range was divided into groups to investigate hardness, relative density and microstructure of M3:2 high-speed steel. Strip and quadrate carbides were observed inside the equiaxed grains. SPS sintering temperature at 900°C can lead to nearly full densification with grain size smaller than 20μm. The hardness and bending strength are higher than that of the conventionally powder metallurgy fabricated ones sintered at 1270°C. However, fracture toughness of the high speed steel is lower than that of the conventional powder metallurgy steels. This can be attributed to the shape and distribution of M6C carbides which reduce the impact toughness of high speed steels.

Spark Plasma Sintering TiAl Alloy from Mechanically Activated Powders

2011 ◽  
Vol 250-253 ◽  
pp. 3309-3312 ◽  
Author(s):  
Zhi Wei Wang ◽  
Hong Cheng ◽  
Hui Ming Cheng
Keyword(s):  
Spark Plasma Sintering ◽  
Tial Alloy ◽  
Sintering Temperature ◽  
Al Alloy ◽  
Tial Alloys ◽  
Fine Grained ◽  
Plasma Sintering ◽  
Short Period ◽  
Spark Plasma ◽  
Higher Temperature

Powder of Ti-46at%Al alloy was synthesized through mechanical activation (MA) and then sintered and concurrently consolidated in a short sintering time of 900 s by using spark plasma sintering (SPS) process. The XRD and SEM profiles show that the microstructures of TiAl alloys contained γ TiAl and small amount α-2 Ti3Al phase, whose amount can be controlled by the sintering temperature. The compacts retained the original fine-grained fully densified bodies by avoiding an excessively high sintering temperature. The alloys sintered at higher temperature with this process showed a coarser microstructure. So it is possible to produce dense nanostructured TiAl alloys by mechanically activated spark plasma sintering (MASPS) within a very short period of time.

TiAl Alloy Spark Plasma Sintered from Mechanically Activated Powders

2011 ◽  
Vol 284-286 ◽  
pp. 2336-2339
Author(s):  
Zhi Wei Wang ◽  
Jun Chen
Keyword(s):  
Spark Plasma Sintering ◽  
Tial Alloy ◽  
Sintering Temperature ◽  
Al Alloy ◽  
Tial Alloys ◽  
Fine Grained ◽  
Plasma Sintering ◽  
Short Period ◽  
Spark Plasma ◽  
Higher Temperature

Powder of Ti-46at%Al alloy was synthesized through mechanical activation (MA) and then sintered and concurrently consolidated in a short sintering time of 900 s by using spark plasma sintering (SPS) process. The XRD and SEM profiles show that the microstructures of TiAl alloys contained γ TiAl and small amount α-2 Ti3Al phase, whose amount can be controlled by the sintering temperature. The compacts retained the original fine-grained fully densified bodies by avoiding an excessively high sintering temperature. The alloys sintered at higher temperature with this process showed a coarser microstructure. So it is possible to produce dense nanostructured TiAl alloys by mechanically activated spark plasma sintering (MASPS) within a very short period of time.

Fabrication of TiAl Intermetallic by Spark Plasma Sintering

2007 ◽  
Vol 336-338 ◽  
pp. 1050-1052 ◽  
Author(s):  
Hai Tao Wu ◽  
Yun Long Yue ◽  
Wei Bing Wu ◽  
Hai Yan Yin
Keyword(s):  
Mechanical Properties ◽  
Intermetallic Compounds ◽  
Spark Plasma Sintering ◽  
Bending Strength ◽  
Sintering Temperature ◽  
Three Point Bending ◽  
The Poor ◽  
High Relative Density ◽  
Plasma Sintering ◽  
Spark Plasma

The γ-TiAl intermetallic compounds were produced at the temperature ranging from 850°C to 1050°C by the Spark Plasma Sintering (SPS) process. The effects of sintering temperature and holding time on the mechanical properties of γ-TiAl intermetallic compounds were investigated. The γ-TiAl intermetallic compounds sintered at 1050°C for 10 min showed a high relative density more than 98%, and had the best three-point bending strength of 643MPa, fracture toughness of 12 MPa·m1/2 and microhardness of 560MPa. The microstructural observations indicated typical characteristics of intergranular fracture, which meant the poor ductility of γ-TiAl intermetallic compounds.

scholarly journals Spark Plasma Sintering of Cobalt Powders in Conjunction with High Energy Mechanical Treatment and Nanomodification

Processes ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 627
Author(s):  
Van Minh Nguyen ◽  
Rita Khanna ◽  
Yuri Konyukhov ◽  
Tien Hiep Nguyen ◽  
Igor Burmistrov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Spark Plasma Sintering ◽  
Bending Strength ◽  
High Energy ◽  
Fine Grained ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Microstructure Density ◽  
High Degree ◽  
Grain Boundary Movement

Spark plasma sintering (SPS) investigations were carried out on three sets of Co specimens: untreated, high energy mechanically (HEMT) pre-treated, and nanomodified powders. The microstructure, density, and mechanical properties of sintered pellets were investigated as a function of various pre-treatments and sintering temperatures (700–1000 °C). Fine-grained sinters were obtained for pre-treated Co powders; nano-additives tended to inhibit grain growth by reinforcing particles at grain boundaries and limiting grain-boundary movement. High degree of compaction was also achieved with relative densities of sintered Co pellets ranging between 95.2% and 99.6%. A direct co-relation was observed between the mechanical properties and densities of sintered Co pellets. For a comparable sinter quality, sintering temperatures for pre-treated powders were lower by 100 °C as compared to untreated powders. Highest values of bending strength (1997 MPa), microhardness (305 MPa), and relative density (99.6%) were observed for nanomodified HEMT and SPS processed Co pellets, sintered at 700 °C.

scholarly journals Spark Plasma Sintering Behavior of Nb-Mo-Si Alloy Powders Fabricated by Hydrogenation-Dehydrogenation Method

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3549 ◽  
Author(s):  
Sung Lee ◽  
Ki Park ◽  
Jang-Won Kang ◽  
Yanghoo Kim ◽  
Hyun-Su Kang ◽  
...  
Keyword(s):  
Spark Plasma Sintering ◽  
Sintering Temperature ◽  
Sintering Behavior ◽  
Powder Metallurgy Method ◽  
Composite Powders ◽  
Plasma Sintering ◽  
Formation Behavior ◽  
Spark Plasma ◽  
Two Phases ◽  
Nb5si3 Phase

In this study, the sintering behaviors of Nb-6Mo-20Si-3Cr (at percentage) in situ composite powders were studied. The Nb alloy powder was fabricated by a hydrogenation-dehydrogenation method, and both the alloy ingot and powders consisted of two phases: An Nb metal phase and the α-Nb5Si3 phase. Consolidation of the alloy powders was performed at 1500, 1600, and 1700 °C using spark plasma sintering, and the microstructures and phases formed at various sintering temperatures were analyzed. Micropores were observed in the compact sintered at 1500 °C due to the lack of complete densification at that temperature. The densification was completed at 1600 °C and the microstructure was slightly coarsened at 1700 °C compared to the microstructure of the compact sintered at 1600 °C. The microstructures prepared by the powder metallurgy method were finer than the microstructure of the ingot prepared by the casting method. The phase formation behavior varied according to the sintering temperature. Specifically, the α-Nb5Si3 phase, which is a stable structure of the Nb5Si3 phase at a low temperature, was transformed to the β-Nb5Si3 phase (which is stable at a high temperature) with an increasing sintering temperature.

Fabrication Processes and Properties of Highly Pure MgAlON Materials

2007 ◽  
Vol 561-565 ◽  
pp. 543-546 ◽  
Author(s):  
Qing Huang ◽  
Yong Huang ◽  
Chang An Wang ◽  
Hou Xing Zhang
Keyword(s):  
Spark Plasma Sintering ◽  
Open Porosity ◽  
Single Phase ◽  
Bending Strength ◽  
Sintering Temperature ◽  
Hot Press ◽  
Plasma Sintering ◽  
Short Period ◽  
Spark Plasma ◽  
Hot Press Sintering

In this paper, the MgAlON ceramic was fabricated by Spark Plasma Sintering (SPS) and hot press sintering respectively. The results showed that highly pure and single-phase MgAlON could be fabricated at lower sintering temperature in a short period through SPS process, compared with the conventional Hot Press sintering (HP) process. The bending strength of MgAlON specimens prepared by SPS process was higher than 500MPa while bending strength of HP specimens was much lower. The open porosity was almost eliminated in SPS MgAlON specimens. Spark Plasma Sintered MgAlON had a single phase of MgAlON while Hot Press Sintered MgAlON had major MgAlON and minor AlN and Al2O3.

Fabrication of Dense Nanostructured Bulk Ceramics by Means of Spark-Plasma-Sintering (SPS) Processing

2016 ◽  
Vol 838-839 ◽  
pp. 225-230 ◽  
Author(s):  
Koji Morita ◽  
Byung Nam Kim ◽  
Hidehiro Yoshida ◽  
Keijiro Hiraga ◽  
Yoshio Sakka
Keyword(s):  
Heating Rate ◽  
Spark Plasma Sintering ◽  
Sintering Temperature ◽  
High Heating Rate ◽  
Fine Grained ◽  
Fine Grain ◽  
Plasma Sintering ◽  
High Heating ◽  
Spark Plasma ◽  
Primary Advantage

In order to fabricate fine-grained and dense nanoceramic materials, the effect of spark-plasma-sintering (SPS) conditions was examined in MgAl2O4 spinel as a reference material. The SPS conditions, such as heating rate and loading temperature, strongly affected the microstructures. Although the density can be improved with decreasing the heating rate to less than 10 °C/min, it requires a long processing time. In order to fully utilize the high heating rate that is a primary advantage of the SPS technique, load controlling is very effective to achieve high density with maintaining fine grain size. An increase in the loading temperature during SPS processing can reduce the residual porosity in a spinel even at the widely used high heating rate of 100 °C/min. This suggests that for the SPS processing in ceramics, the load controlling is an important factor as well as the heating rate and sintering temperature.

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