Analysis of melting in a subcooled two-component metal powder layer with constant heat flux

Heat Transfer Engineering

Chen

2011

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Ablation is the most common approach for thermal management for reentry of the spacecraft to the atmosphere. An analytical solution of the ablation of a two-layer composite, which includes an ablative layer and a nonablative substrate, subject to a Gaussian heat flux is presented in this paper. The problem is divided into five stages and the temperature distributions in both layers in the five stages are obtained using an integral approximate method. The locations of ablation interface, thermal penetration depth, and ablation rate are obtained and the effects of Stefan number, subcooling parameter, thickness of the ablative material, and ratio of thermal diffusivities between two materials are investigated.

Section: Physical Modelmentioning

confidence: 99%

An Integral Approximate Solution to Ablation of a Two-Layer Composite with a Temporal Gaussian Heat Flux

Yang

Heat Transfer Engineering

Chen

2011

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“…Zhang et al [8] analytically solved a one-dimensional melting problem in a semi-infinite powder bed containing a twocomponent powder mixture subjected to a constant heat flux heating, of which the shrinkage is considered. Chen et al [9] obtained an analytical solution of one-dimensional melting of the two-component metal powder layer with finite thickness. A two-dimensional steady-state lasermelting problem using an ADI scheme with a false transient formulation was solved by Basu et al [10].…”

Section: Introductionmentioning

confidence: 99%

Two-dimensional modeling of sintering of a powder layer on top of nonporous substrate

Chen

Front. Mech. Eng. China

2010

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Selective laser sintering (SLS) of a twocomponent metal powder layer on the top of multiple sintered layers by a moving Gaussian laser beam is modeled. The loose metal powder layer is composed of a powder mixture with significantly different melting points. The physical model that accounts the shrinkage induced by melting is described by using a temperature-transforming model. The effects of the porosity and the thickness of the atop loose powder layer with different numbers of the existing sintered metal powder layers below on the sintering process are numerically investigated. The present work will provide a better understanding to simulate much more complicated three-dimensional SLS process.

“…Pulsed lasers with pulse widths ranging from milliseconds [8,9] to nanoseconds [10][11][12] have been investigated. Evaporation recoil force during nanosecond laser sintering can overcome the surface tension force acting on the melt, therefore improving the cohesion of the powder particles.…”

Section: Introductionmentioning

confidence: 99%

Solid-Liquid-Vapor Phase Change of a Subcooled Metal Powder Particle Subjected to Nanosecond Laser Heating

Shi

Nanoscale and Microscale Thermophysical Engineering

Konrad

2007

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Solid-liquid-vapor phase change of a metal particle subjected to nanosecond pulse laser heating is investigated analytically. Temperature distribution in the particle, locations of solid-liquid and liquid-vapor interface, saturation temperature, and recoil pressure around the particle were obtained analytically. Effects of physical parameters including laser fluence, pulse width, initial temperature, and particle diameter on the phase change were investigated. The results show that a decrease in particle radius and laser pulse width, or an increase in laser fluence and initial particle temperature, results in an earlier melting time, a higher surface temperature, more evaporated material, and a higher final thermalized temperature.