In this work, dimensional analysis is used to develop a general mathematical model to predict bulk density of SLMed components taking volumetric energy density, scanning speed, powder’s thermal conductivity, specific heat capacity, and average grain diameter as independent variables. Strong relation between dependent and independent dimensionless products is observed. Inconel 718 samples were additively manufactured and a particular expression, in the form of a power-law polynomial, for its bulk density, in the working domain of the independent dimensionless product, was obtained. It is found that with longer laser exposure time, and lower scanning speed, better densification is attained. Likewise, volumetric energy density has a positive influence on bulk density. The negative effect of laser power in bulk density is attributed to improper process conditions leading to powder particle sublimation and ejection. A maximum error percentage between experimental and predicted bulk density of 3.7119% is achieved, which corroborates the accuracy of our proposed model. A general expression for determining the scanning speed, with respect to laser power, needed to achieve highly dense components, was derived. The model’s applicability was further validated considering SLMed samples produced by AlSi10Mg and Ti6Al4V alloys. This article elucidates how to tune relevant manufacturing parameters to produce highly dense SLM parts using mathematical expressions derived from Buckingham’s π- theorem.

The present research work focuses on depositing multi-walled carbon nanotubes (MWCNTs) onto aluminum parts to modify their electrical and thermal properties by an electrodeposition process (EDP). This film coated over the sample surface creates a network of high conductive thin layer that promotes free electron flow and heat-loss reduction. Experimental measurements on the metallic surface part show an increment of the electrical conductivity of 9.6% for the sample coated with 0.05 mg/mL of MWCNTs with a heat dissipation increase of 36%.

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Greases are essential in the electrical industry for the purpose of minimizing wear and coefficient of friction (COF) between the components of circuit breakers. Nowadays some researchers have explored the addition of nanoparticles to enhance their tribological properties. In this study, tribological tests were performed on different greases employed for the electrical industry. CuO and ZnO nanoparticles were homogeneously dispersed into the greases, varying their concentration (0.01 wt.%, 0.05 wt.%, and 0.10 wt.%). A four-ball tribotest, according to ASTM D-2266, and a ball-on-disk tribotest, according to ASTM G-99, were performed in order to analyze the wear scar diameter (WSD), COF, wear mass loss and worn area. The worn materials were characterized with an optical 3D profilometer measurement system. Anti-wear properties were enhanced up to 29.30% for the lithium complex grease (LG) with no nanoparticles added, in comparison with the aluminum complex grease (AG), providing a much better tribological performance; in the ball-on-disk tribotests, a 72.80% and a 15.74% reduction in the mass loss and COF were achieved, respectively. The addition of nanoparticles was found to provide improvements of 5.31% in WSD for the AG grease and 34.49% in COF for the LG grease. A pilot test was performed following the security test UL489, achieving a reduction of 45.17% in the worn area achieved by LG grease compared to AG grease.