The novel rapidly solidified TiC/FeAl composite coatings were fabricated by laser cladding on the substrate of 1Cr18Ni9Ti stainless steel, particular emphasis has been placed on the growth morphologies of TiC carbide ...The novel rapidly solidified TiC/FeAl composite coatings were fabricated by laser cladding on the substrate of 1Cr18Ni9Ti stainless steel, particular emphasis has been placed on the growth morphologies of TiC carbide and its growth mechanism under a constant solidification conditions. Results show that the growth morphology of TiC carbide strongly depends upon the nucleation process and mass transportation process of TiC forming elements in laser melt pool. With increasing amount of titanium and carbon in melt pool, the growth morphology of TiC carbide changes from block like to star like and well developed dendrite. As the amount of titanium and carbon increases further, TiC carbide particles are found to be irregular polyhedral block. Although the growth morphologies of TiC are various,their advancing fronts are all faceted, illustrating that TiC carbide grows by the mechanism of lateral ledge growth.展开更多
The fracture behaviors of DO 3 ordered Fe 28Al alloys with or without V addition were studied. The results show that addition of element V into Fe Al alloy can improve the mechanical properties of the alloy. Contraste...The fracture behaviors of DO 3 ordered Fe 28Al alloys with or without V addition were studied. The results show that addition of element V into Fe Al alloy can improve the mechanical properties of the alloy. Contrasted with transgranular fracture of Fe 3Al alloy at room temperature, the Fe 3Al containing V has intergranular and transgranular cleavage mixed fracture mode. The theoretical calculation conforms that V addition could increase cleavage strength of Fe 3Al alloy from 98.405 7 kJ/mol to 173.144 5 kJ/mol in 〈111〉 direction and from 29.660 4 kJ/mol to 47.673 0 kJ/mol in 〈100〉 direction.展开更多
When Cr, Mo and Ti were added to Fe Al/Al 2O 3 composite, the bending strength and fracture toughness of the composite were increased sharply. The highest value of bending strength can exceed 600 MPa and the average v...When Cr, Mo and Ti were added to Fe Al/Al 2O 3 composite, the bending strength and fracture toughness of the composite were increased sharply. The highest value of bending strength can exceed 600 MPa and the average value of fracture toughness exceed 12 MPa·m 1/2 . With increasing content of Mo and Ti, the bending strength and fracture toughness both express the trend of increasing first and then decreasing. When the alloying elements were added to the composites the alloying extent is improved. The fracture mode of the composites are mainly transcrystalline.展开更多
文摘The novel rapidly solidified TiC/FeAl composite coatings were fabricated by laser cladding on the substrate of 1Cr18Ni9Ti stainless steel, particular emphasis has been placed on the growth morphologies of TiC carbide and its growth mechanism under a constant solidification conditions. Results show that the growth morphology of TiC carbide strongly depends upon the nucleation process and mass transportation process of TiC forming elements in laser melt pool. With increasing amount of titanium and carbon in melt pool, the growth morphology of TiC carbide changes from block like to star like and well developed dendrite. As the amount of titanium and carbon increases further, TiC carbide particles are found to be irregular polyhedral block. Although the growth morphologies of TiC are various,their advancing fronts are all faceted, illustrating that TiC carbide grows by the mechanism of lateral ledge growth.
文摘The fracture behaviors of DO 3 ordered Fe 28Al alloys with or without V addition were studied. The results show that addition of element V into Fe Al alloy can improve the mechanical properties of the alloy. Contrasted with transgranular fracture of Fe 3Al alloy at room temperature, the Fe 3Al containing V has intergranular and transgranular cleavage mixed fracture mode. The theoretical calculation conforms that V addition could increase cleavage strength of Fe 3Al alloy from 98.405 7 kJ/mol to 173.144 5 kJ/mol in 〈111〉 direction and from 29.660 4 kJ/mol to 47.673 0 kJ/mol in 〈100〉 direction.
文摘When Cr, Mo and Ti were added to Fe Al/Al 2O 3 composite, the bending strength and fracture toughness of the composite were increased sharply. The highest value of bending strength can exceed 600 MPa and the average value of fracture toughness exceed 12 MPa·m 1/2 . With increasing content of Mo and Ti, the bending strength and fracture toughness both express the trend of increasing first and then decreasing. When the alloying elements were added to the composites the alloying extent is improved. The fracture mode of the composites are mainly transcrystalline.
