Fracture Toughness and Magnetic Properties of Sm2Co17-Based Magnets

2013 ◽  
Vol 645 ◽  
pp. 81-84 ◽  
Author(s):  
Ai Kun Li ◽  
Li Ya Li ◽  
Yuan Dong Peng ◽  
Jian Hong Yi
Keyword(s):  
Fracture Toughness ◽  
Magnetic Properties ◽  
High Performance ◽  
Maximum Energy ◽  
Crack Deflection ◽  
Toughening Mechanisms ◽  
Screw Dislocations ◽  
Yield Plateau ◽  
High Toughness ◽  
Type Magnet

We present our findings of increased fracture toughness in high performance Sm2Co17-type magnet. The new Sm(Co 0.65 Fe 0.24 Cu 0.08 Zr 0.03)7.6magnet exhibits remanence of 11.13 kGs, maximum energy of 30.2 MGOe. This magnet shows not only a superhigh fracture toughness of 5.56 MPa m 1/2 but also distinguished yielding combined with an enhanced plastic plateau of 30 % to failure. It has been found that debonding, crack deflection, crac k branching and bridging are the major toughening mechanisms for the observed high toughness and long yield plateau. Long and straight screw dislocations observed in Sm rich precipitates accelerate the debonding of Sm rich grains.

Failure Behaviour of High Toughness Multi-Layer Si3N4 and Si3N4-TiN Based Laminates

2005 ◽  
Vol 290 ◽  
pp. 175-182 ◽  
Author(s):  
Gurdial Blugan ◽  
Richard Dobedoe ◽  
I. Gee ◽  
Nina Orlovskaya ◽  
Jakob Kübler
Keyword(s):  
Fracture Toughness ◽  
High Temperature ◽  
Residual Stresses ◽  
Crack Propagation ◽  
Failure Mechanisms ◽  
High Strength ◽  
Crack Deflection ◽  
High Toughness ◽  
Energy Absorbing ◽  
Crack Bifurcation

Multi-layer laminates were produced using alternating layers of Si3N4 and Si3N4+TiN. The differences in the coefficient of thermal expansions between the alternating layers lead to residual stresses after cooling. These are compressive in the Si3N4 layers and tensile in the Si3N4+TiN layers. The existence of these stresses in the laminates effect the crack propagation behaviour during failure. Different designs of laminates were produced with external layers under compression and tension exhibiting different failure mechanisms. Facture toughness was measured by SEVNB method. In systems with external layers under compression the measured fracture toughness was up to three times that of Si3N4, i.e. up to 17 MPa m1/2. In systems with external layers under tension during failure the energy absorbing effects of crack deflection and crack bifurcation were obtained. High temperature tests were performed to determine the onset temperature for residual stresses in these laminates. Micro-laminates with compressive layers of only 30 µm thickness with high strength and fracture toughness and were manufactured.

Nanocrystalline and Nanostructured High-Performance Permanent Magnets

2001 ◽  
Vol 674 ◽  
Author(s):  
D. Goll ◽  
W. Sigle ◽  
G.C. Hadjipanayis ◽  
H. Kronmüller
Keyword(s):  
Magnetic Properties ◽  
High Performance ◽  
Permanent Magnets ◽  
Maximum Energy ◽  
High Quality ◽  
Hardening Mechanism ◽  
Temperature Dependences ◽  
Complex Correlation ◽  
Energy Products

ABSTRACTThe rather complex correlation between the microstructure and the magnetic properties is demonstrated for two types of high-quality RE-TM permanent magnets (pms), namely nanocrystalline RE2Fe14B (RE = Nd,Pr) and nanostructured Sm2(Co,Cu,Fe,Zr)17 pms. The detailed analysis of this correlation for both pm materials leads to a quantitative comprehension of the hardening mechanism enabling the optimization of their magnetic properties and temperature dependences. In the case of RE2Fe14B, isotropic bonded pms are fabricated showing maximum energy products in the order of 90 kJ/m3. In the case of Sm2(Co,Cu,Fe,Zr)17, magnets with excellent high-temperature magnetic properties are tailored. Hereby, the investigations in addition provide important clues to the evolution of the characteristic microstructural and magnetic properties and to the role of the involved elements.

scholarly journals Development of a High-Performance-Ferrite Magnet Fabrication Process without Sintering Additives

2021 ◽  
Vol 59 (8) ◽  
pp. 551-559
Author(s):  
Pyeong-Yeol Yu ◽  
Min-Ho Kim ◽  
Young-Min Kang
Keyword(s):  
Magnetic Properties ◽  
Saturation Magnetization ◽  
High Performance ◽  
Secondary Phase ◽  
Batch Process ◽  
Maximum Energy ◽  
Magnetic Flux Density ◽  
Sintering Additives ◽  
Energy Product ◽  
Hard Magnetic Properties

Sintered M-type hexaferrites with the chemical formula of Sr0.3Ca0.4La0.3Fe9.8Co0.2-xMnxSi0.135O19-d (x = 0, 0.05, 0.1, 0.2) and Sr0.3Ca0.4La0.3Fe9.8-yCo0.2MnySi0.135O19-d (y = 0.05, 0.1, 0.2) were prepared by conventional solid station reaction routes. A high sintering density of more than 95% of the theoretical density was achieved in all hexaferrite samples when calcination was carried out at 1100 oC for 4 h, followed by sintering at 1230-1250 oC for 2 h without the use of sintering additives. High saturation magnetization and coercivity were achieved simultaneously at the x = 0.05 composition, where Mn replaces part of the Co. The secondary phase Fe2O3 generated by the initial addition of SiO2 was gradually reduced when the Fe contented was decreased in the Sr0.3Ca0.4La0.3Fe9.8-zCo0.15Mn0.05Si0.135O19-d samples, and a single M-type hexaferrite phase was confirmed in the Sr0.3Ca0.4La0.3Fe8.3Co0.15Mn0.05Si0.135O19-d (z = 1.5) sample, which also exhibited optimized hard magnetic properties, with a saturation magnetization of 4581 G and coercivity of 4771 Oe. Anisotropic sintered magnets were fabricated using the optimized composition, and showed excellent hard magnetic properties, with a remanent magnetic flux density of 4400 G and intrinsic coercivity of 4118 Oe, and a maximum energy product of 4.72 M·G·Oe. This result is very promising because high magnet performance can be achieved with a single batch process without the need for sintering additives during the process.

Fracture Toughness of Si3N4 Based Ceramics with Rare-Earth Oxide Sintering Additives

2009 ◽  
Vol 409 ◽  
pp. 377-381 ◽  
Author(s):  
Peter Tatarko ◽  
Štefánia Lojanová ◽  
Ján Dusza ◽  
Pavol Šajgalík
Keyword(s):  
Fracture Toughness ◽  
Rare Earth ◽  
Silicon Nitride ◽  
Aspect Ratio ◽  
Rare Earth Oxide ◽  
Rare Earth Oxides ◽  
Crack Deflection ◽  
Indentation Fracture ◽  
Toughening Mechanisms ◽  
Sintering Additives

Fracture toughness of hot-pressed silicon nitride and Si3N4+SiC nanocomposites prepared with different rare-earth oxides (La2O3, Sm2O3, Y2O3, Yb2O3, Lu2O3) sintering additives have been investigated by Chevron Notched Beam, Indentation Strength and Indentation Fracture techniques. The fracture toughness values of composites were lower due to the finer microstructures and the lack of toughening mechanisms. In the Si3N4 with higher aspect ratio (Lu or Yb additives) crack deflection occurred more frequently compared to the Si3N4 doped with La or Y, which was responsible for the higher fracture toughness.

Mechanical and Fracture Properties of Bamboo

2006 ◽  
Vol 312 ◽  
pp. 15-20 ◽  
Author(s):  
It Meng Low ◽  
Z.Y. Che ◽  
Bruno A. Latella ◽  
K.S. Sim
Keyword(s):  
Fracture Toughness ◽  
Mechanical Performance ◽  
Elastic Stiffness ◽  
Crack Deflection ◽  
Vickers Indentation ◽  
Fracture Properties ◽  
Depth Profiles ◽  
High Toughness ◽  
Synchrotron Radiation Diffraction ◽  
Mechanical And Fracture Properties

The microstructure, mechanical, impact and fracture properties of Australian bamboo have been investigated. The graded composition and property has been confirmed by depth-profiles obtained by synchrotron radiation diffraction and Vickers indentation. The mechanical performance of bamboo is stronly dependent on age. Results showed that young bamboo has higher strength, elastic stiffness and fracture toughness than its old counterpart. Both crack-deflection and crackbridging are the major energy dissipative processes for imparting a high toughness in bamboo.

AISI 4320

Alloy Digest ◽  
1959 ◽  
Vol 8 (2) ◽  
Keyword(s):  
Fracture Toughness ◽  
Corrosion Resistance ◽  
Physical Properties ◽  
Heat Treating ◽  
Case Hardening ◽  
High Toughness ◽  
Nickel Chromium ◽  
Steel Mills ◽  
Shock Resistance ◽  
Case Hardening Steel

Abstract AISI 4320 is a nickel-chromium-molybdenum case hardening steel having high toughness and shock resistance. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SA-80. Producer or source: Alloy steel mills and foundries.

AISI 8630

Alloy Digest ◽  
1956 ◽  
Vol 5 (10) ◽  
Keyword(s):  
Fracture Toughness ◽  
Low Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
Alloy Steel ◽  
Heat Treating ◽  
High Tempering ◽  
High Toughness ◽  
Steel Mills ◽  
Temperature Performance

Abstract AISI 8630 is a chromium, nickel, molybdenum alloy steel. It is of the moderate deep hardening type and develops high toughness at high tempering temperatures. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on low temperature performance as well as forming, heat treating, machining, and joining. Filing Code: SA-49. Producer or source: Alloy steel mills and foundries.

ARMCO PH 13-8Mo

Alloy Digest ◽  
1990 ◽  
Vol 39 (2) ◽  
Keyword(s):  
Fracture Toughness ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Stress Corrosion ◽  
Tensile Properties ◽  
High Performance ◽  
High Strength ◽  
Heat Treating ◽  
Temperature Performance

Abstract ARMCO PH 13-8Mo is designed for high-performance applications requiring high strength coupled with excellent resistance to corrosion and stress corrosion. It has excellent toughness, good transverse properties and excellent forgeability. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on low and high temperature performance, and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-224. Producer or source: Baltimore Specialty Steels Corporation. Originally published May 1969, revised February 1990.

DILLIMAX 500

Alloy Digest ◽  
2012 ◽  
Vol 61 (3) ◽  
Keyword(s):  
Fracture Toughness ◽  
Yield Strength ◽  
Physical Properties ◽  
Structural Steel ◽  
Tensile Properties ◽  
High Strength ◽  
Heat Treating ◽  
Fine Grained ◽  
High Toughness ◽  
Minimum Yield

Abstract Dillimax 500 is a high-strength quenched and tempered, fine-grained structural steel with a minimum yield strength of 500 MPa (72 ksi). Plate is delivered in three qualities: basic, high toughness, and extra tough. This datasheet provides information on composition, physical properties, and tensile properties as well as fracture toughness. It also includes information on surface qualities as well as forming, heat treating, and joining. Filing Code: SA-645. Producer or source: Dillinger Hütte GTS.

CYCLOPS N9

Alloy Digest ◽  
1958 ◽  
Vol 7 (6) ◽  
Keyword(s):  
Fracture Toughness ◽  
Physical Properties ◽  
Tensile Properties ◽  
Fatigue Resistance ◽  
Heat Treating ◽  
High Toughness

Abstract CYCLOPS N-9 is a chromium-nickel oil hardening steel with high toughness and fatigue resistance. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on forming, heat treating, machining, and joining. Filing Code: TS-71. Producer or source: Cyclops Corporation.

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