Título

Dimensional analysis for tuning Selective Laser Melting parameters for near-full density of Inconel 718

Autor

ALEX ELIAS ZUÑIGA

Nivel de Acceso

Acceso Abierto

Resumen o descripción

https://orcid.org/0000-0002-5661-2802

Selective laser melting is a powder bed fusion process that allows the production of metallic pieces of high geometrical complexity. Full densification is regarded as fundamental to

achieve mechanical integrity. Nevertheless, doing so for a new material requires an intensive,

in time and resources, experimentation stage in order to set proper manufacturing parameters.

In this work, dimensional analysis is used to develop a general mathematical model on bulk

density of SLMed components taking volumetric energy density, scanning speed and powder’s thermal conductivity, specific heat capacity and average grain diameter as independent

variables. Strong relation between dependent and independent dimensionless products was

observed. Bulk density is found to be proportional to volumetric energy density and be affected by scanning speed by a factor of negative two. Inconel 718 probes were produced and

a particular expression, in the form of a first order polynomial, for its bulk density,in the independent dimensionless product π1 range from 3.17x10−8

to 4.6 x10−8 was obtained. In this

range, better densification is achieved at lower scanning speed and lower laser power. The first

is related to higher exposure time and ensuring full melt of the powder, and the second may

be due to powder particle sublimation / ejection due to improperly large laser power conditions. An average relative density of 95.218% was measured. An average error percentage of

1.6503% between experimental and predicted bulk density (and dimensionless density) was

achieved. A mathematical tool for tuning scanning speed to achieve full densification, with

respect to laser power, was developed. Moreover, particular conditions for achieving so for

Inconel 718 in the π1 range was provided.

Master of Science in Nanotechnology

Editor

Instituto Tecnológico y de Estudios Superiores de Monterrey

Fecha de publicación

junio de 2020

Tipo de publicación

Tesis de maestría

Recurso de información

Formato

application/pdf

Idioma

Inglés

Audiencia

Investigadores

Repositorio Orígen

Repositorio Institucional del Tecnológico de Monterrey

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