CFPC material characteristics and SLS prototyping process

Abstract

PurposeThe purpose of this paper is to characterize the material properties of carbon fiber polyamide composite (CFPC) used in a 3D rapid prototyping process based upon selective laser sintering (SLS) and demonstrate that the SLS process introduces a bias in the micro‐fiber orientation such that the CFPC solid is an orthotropic structural material.Design/methodology/approachMaterial coupons for tensile tests from each of the orthogonal planes are created using the SLS process. After tensile testing, the coupons are examined under scanning electron microscopy to verify the micro‐fiber orientation bias. A complex 3D structure developed utilizing the CFPC material is subjected to modal testing to extract the natural frequencies. These frequencies are compared to predictive numerical analysis results from computer‐aided engineering (CAE) software to validate the coupon test results.FindingsThis paper proves that the CFPC solid material is orthotropic after the SLS process and that the process itself creates bias in the micro‐fiber orientation. Predictions of natural frequencies from CAE software for a complex 3D structure created from CFPC are within 2 percent of the actual natural frequencies determined during modal testing.Practical implicationsThe paper has determined the tensile material characteristics of solid CFPC correcting the original material data sheet information which lists the solid CFPC as isotropic with much stronger tensile characteristics. It has also provided evidence of the bias that SLS introduces to embedded micro‐fibers during the rapid‐prototyping process.Originality/valueThe paper deals with experimental work on determining the material characteristics of a relatively new composite material for which very little test data exists in literature. In particular, an original contribution is demonstration of the micro‐fiber orientation bias introduced by the SLS process.