An Algorithm for the Energy Deposition by Fast Electrons

2009

Metall Mater Trans A

Iron-based surface composites were fabricated with Fe-based metamorphic alloy powders and VC powders by high-energy electron beam irradiation, and the correlation of their microstructure with hardness and fracture toughness was investigated. Mixtures of metamorphic powders and VC powders were deposited on a plain carbon steel substrate, and then the electron beam was irradiated on these powders without flux, to fabricate surface composites. The composite layers 1.3 to 1.8 mm in thickness contained a large amount (up to 47 vol pct) of hard Cr 2 B and V 8 C 7 particles formed in eutectic colony regions and inside colonies, respectively. The hardness of the surface composites was approximately 2 to 4 times greater than that of the substrate because of Cr 2 B and V 8 C 7 particles. According to the microfracture observation of the composite fabricated with mixing 30 wt pct VC powders, microcracks initiated at coarse V 8 C 7 particles ins inside colonies as well as at Cr 2 B particles in colony regions, and were connected with other microcracks in a zigzag shape. Thus, it showed a higher fracture toughness and hardness twice as high as the composite fabricated without mixing VC powders.

Section: Discussionmentioning

confidence: 99%

Correlation of Microstructure, Hardness, and Fracture Toughness of Fe-Based Surface Composites Fabricated by High-Energy Electron Beam Irradiation with Fe-Based Metamorphic Alloy Powders and VC Powders

Nam

2009

Metall Mater Trans A

“…where V 5 acceleration voltage, I 5 beam current, v 5 beam moving speed, l 5 beam scanning width, and f 5 beam reflection coefficient, which was calculated to be 0.08 by Tabata et al [21] The heat input of the F1 specimen fabricated with the beam current of 55 mA is calculated to be 4.05 kJ/cm 2 , which is transferred to the material through a process of electron energy loss. Oh et al [12] investigated the formation processes of the surface composite layer by analyzing the electron energy loss from the surface, and explained them as (1) melting of flux and the substrate surface, (2) melting of metamorphic powders covered by the melted substrate surface, and (3) formation of the surface composite layer in the melted pool during solidification.…”

Section: Discussionmentioning

confidence: 99%

Correlation of microstructure with hardness and wear resistance of surface composites fabricated by high-energy electron beam irradiation of Fe-based metamorphic powders

Nam

et al. 2006

Metall Mater Trans A

In this study, surface composites were fabricated with Fe-based metamorphic powders by high-energy electron beam irradiation, and the correlation of their microstructure with hardness and wear resistance was investigated. Fe-based metamorphic powders were deposited on a plain carbon steel substrate, and then electron beam was irradiated on these powders without flux to fabricate a one-layered surface composite. A two-layered surface composite was also fabricated by irradiating electron beam again onto the powders deposited on the one-layered surface composite. The composite layers of 1.3;1.9 mm in thickness were homogeneously formed without defects and contained a large amount (up to 48 vol pct) of hard and fine Cr 2 B crystalline phases in the Cr 0.19 Fe 0.7 Ni 0.11 matrix. Since the hardness and wear resistance of the surface composite layers were directly influenced by hard Cr 2 B phases, they were two to three times greater than those of the steel substrate. In particular, the twolayered surface composite showed a high hardness of ;300 VHN even at 750°C, as well as at room temperature, because Cr 2 B phases and the Cr 0.19 Fe 0.7 Ni 0.11 matrix were hard and thermally stable.

“…The experimental curve of the density distribution of absorbed energy for PETN [8] is satisfactorily described by equation [5,6]:…”

Section: Problem Statementmentioning

confidence: 99%

Ignition of organic explosives by an electron beam

Ivanov

Khaneft

2015

EPJ Web of Conferences

Abstract.A numerical simulation of the ignition of organic explosives (PETN, HMX, RDX, TATB) with an electron beam was performed. A criterion for the ignition of energetic materials with a melting point below the temperature of ignition is obtained. The results of numerical calculations of the critical energy density of the electron beam are consistent with the criterion of ignition. Calculations of the critical energy density of PETN ignition in good agreement with the experiment. The most sensitive is PETN and the most heat-resistant is TATB.