High entropy alloy borides prepared by powder metallurgy process and the enhanced fracture toughness by addition of yttrium

2021 ◽  
Vol 257 ◽  
pp. 123715
Author(s):  
Ying Long ◽  
Jintao Che ◽  
Zong Wu ◽  
Hua-Tay Lin ◽  
Fenglin Zhang
Keyword(s):  
Fracture Toughness ◽  
Powder Metallurgy ◽  
High Entropy Alloy ◽  
High Entropy ◽  
Powder Metallurgy Process ◽  
Metallurgy Process

scholarly journals Microstructure and Mechanical Properties of Sintered and Heat-Treated HfNbTaTiZr High Entropy Alloy

Metals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1324 ◽  
Author(s):  
Jaroslav Málek ◽  
Jiří Zýka ◽  
František Lukáč ◽  
Jakub Čížek ◽  
Lenka Kunčická ◽  
...  
Keyword(s):  
Powder Metallurgy ◽  
Dendritic Structure ◽  
Cold Isostatic Pressing ◽  
High Entropy Alloy ◽  
High Entropy ◽  
Arc Melting ◽  
Powder Metallurgy Process ◽  
Heat Treated ◽  
Near Net Shape ◽  
Metallurgy Process

High entropy alloys (HEAs) have attracted researchers’ interest in recent years. The aim of this work was to prepare the HfNbTaTiZr high entropy alloy via the powder metallurgy process and characterize its properties. The powder metallurgy process is a prospective solution for the synthesis of various alloys and has several advantages over arc melting (e.g., no dendritic structure, near net-shape, etc.). Cold isostatic pressing of blended elemental powders and subsequent sintering at 1400 °C for various time periods up to 64 h was used. Certain residual porosity, as well as bcc2 (Nb- and Ta-rich) and hcp (Zr- and Hf-rich) phases, remained in the bcc microstructure after sintering. The bcc2 phase was completely eliminated during annealing (1200 °C/1h) and subsequent water quenching. The hardness values of the sintered specimens ranged from 300 to 400 HV10. The grain coarsening during sintering was significantly limited and the maximum average grain diameter after 64 h of sintering was approximately 60 μm. The compression strength at 800 °C was 370 MPa and decreased to 47 MPa at 1200 °C. Porosity can be removed during the hot deformation process, leading to an increase in hardness to ~450 HV10.

CARPENTER MICRO-MELT A11

Alloy Digest ◽  
2001 ◽  
Vol 50 (5) ◽  
Keyword(s):  
Fracture Toughness ◽  
Wear Resistance ◽  
High Temperature ◽  
Powder Metallurgy ◽  
Heat Treating ◽  
Vanadium Content ◽  
Bend Strength ◽  
Temperature Performance ◽  
Powder Metallurgy Process ◽  
Metallurgy Process

Abstract Carpenter Micro-Melt A11 is a tool steel with a high vanadium content. It is made by the Micro-Melt powder metallurgy process. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and bend strength as well as fracture toughness. It also includes information on high temperature performance and wear resistance as well as heat treating and machining. Filing Code: TS-587. Producer or source: Carpenter. Revision of Alloy Digest TS-571, January 2000.

CARPENTER MICRO-MELT T-15 ALLOY

Alloy Digest ◽  
1997 ◽  
Vol 46 (1) ◽  
Keyword(s):  
Fracture Toughness ◽  
Wear Resistance ◽  
Powder Metallurgy ◽  
Machine Tools ◽  
High Speed ◽  
Heat Treating ◽  
High Carbon ◽  
Powder Metallurgy Process ◽  
Red Hardness ◽  
Metallurgy Process

Abstract Carpenter Micro-Melt T-15 Alloy is a high-speed tool steel made by the powder metallurgy process. The alloy is high carbon with tungsten, cobalt, and vanadium for red hardness and excellent abrasion resistance. Applications include machine tools and cutters. This datasheet provides information on composition, physical properties, hardness, and elasticity as well as fracture toughness. It also includes information on wear resistance as well as forming and heat treating. Filing Code: TS-549. Producer or source: Carpenter.

scholarly journals Effect of Copper Addition on the AlCoCrFeNi High Entropy Alloys Properties via the Electroless Plating and Powder Metallurgy Technique

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 540
Author(s):  
Mohamed Ali Hassan ◽  
Hossam M. Yehia ◽  
Ahmed S. A. Mohamed ◽  
Ahmed Essa El-Nikhaily ◽  
Omayma A. Elkady
Keyword(s):  
Compressive Strength ◽  
Powder Metallurgy ◽  
Atomic Radius ◽  
The Other ◽  
High Entropy Alloy ◽  
Coating Process ◽  
High Entropy Alloys ◽  
Powder Metallurgy Technique ◽  
Copper Metal ◽  
High Entropy

To improve the AlCoCrFeNi high entropy alloys’ (HEAs’) toughness, it was coated with different amounts of Cu then fabricated by the powder metallurgy technique. Mechanical alloying of equiatomic AlCoCrFeNi HEAs for 25 h preceded the coating process. The established powder samples were sintered at different temperatures in a vacuum furnace. The HEAs samples sintered at 950˚C exhibit the highest relative density. The AlCoCrFeNi HEAs model sample was not successfully produced by the applied method due to the low melting point of aluminum. The Al element’s problem disappeared due to encapsulating it with a copper layer during the coating process. Because the atomic radius of the copper metal (0.1278 nm) is less than the atomic radius of the aluminum metal (0.1431 nm) and nearly equal to the rest of the other elements (Co, Cr, Fe, and Ni), the crystal size powder and fabricated samples decreased by increasing the content of the Cu wt%. On the other hand, the lattice strain increased. The microstructure revealed that the complete diffusion between the different elements to form high entropy alloy material was not achieved. A dramatic decrease in the produced samples’ hardness was observed where it decreased from 403 HV at 5 wt% Cu to 191 HV at 20 wt% Cu. On the contrary, the compressive strength increased from 400.034 MPa at 5 wt% Cu to 599.527 MPa at 15 wt% Cu with a 49.86% increment. This increment in the compressive strength may be due to precipitating the copper metal on the particles’ surface in the nano-size, reducing the dislocations’ motion, increasing the stiffness of produced materials. The formability and toughness of the fabricated materials improved by increasing the copper’s content. The thermal expansion has increased gradually by increasing the Cu wt%.

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