Experimental Investigations On Surface Roughness And Fatigue Strength Characteristics Of Inhibition Sintered Polyamide 12 Parts

Abstract

The Additive Manufacturing (AM) technology has revolutionized newlinethe production system in terms of fabricating geometrically complex parts at newlinea lower cost and shorter manufacturing lead time. The selective inhibition newlinesintering (SIS) process is a novel low-cost AM technology that builds parts newlinedirectly from a three-dimensional computer-aided design (CAD) model by newlinejoining materials layer-by-layer. It is a modified version of the selective laser newlinesintering (SLS) system where the expensive high-power and costly CO2 laser newlineis replaced by a low-cost infrared heater. The basic principle of the SIS system newlineis sintering powder particles in the parts body and preventing the powder newlineparticles at periphery the of the part from sintering. newlineEven though the SIS system has many advantages over the existing newlinepowder-based technology, it is not commercialized yet. This is because the newlineSIS system is a nascent technology, and hence, it is not well investigated and newlineprocess parameters are not fully characterized for most common engineering newlinepolymer materials including polyamide 12. However, polyamide 12 possesses newlinea wide sintering window and has many engineering applications. As a result,it is one of the most common engineering materials that are being processed newlineby powder-based AM processes such as SLS and multi-jet fusion. Therefore, newlinethis research work has focused on the characterization of the SIS process newlinevariables to fabricate parts from polyamide 12 powdered material and newlineoptimize the fatigue strength and surface roughness of the sintered parts. newlineFor this study, a low-cost SIS system was designed and developed newlinewith a build volume of 200mm x 250mm x 200mm. Inhibitor solution material newlinewas tested, and potassium iodide (KI) was selected as an inhibition material newlinefor Polyamide (PA) 12 powder due to its uniform dispersion and penetration. newlineThe inhibitor solution was prepared from a saturated aqueous solution of newlinepotassium iodide. The inhibition property of the solution was improved by adding Isopropyl alcohol to it.The surface ro