Ferro fundido nodular a partir de machos impressos em 3D para nova geração de pistões de motor

Abstract

The piston engine is one of the most critical components of the automotive industry due to cyclical stresses they are subjected to. In order to adapt to new environmental legislations, the material selection for the manufacture of piston engines become even more challenging. Nodular cast iron (NCI) is a sustainable option for piston engines. Its mechanical properties can be successfully manipulated through heat treatment to achieve tensile strengths as high as 1400 MPa when austempered and 900 MPa when normalized. In addition, the use of additive manufacturing, producing cores in 3D printers, allows greater freedom of design and the production of components with few geometric restrictions. In this work, mechanical, physical and microstructure properties at high temperatures of an EN-GJS-800-02 NCI alloy were evaluated. Results have shown that thermal conductivity of this material reaches a maximum value of 31 W/Km at 400 °C, the usual working temperature of ICE components. The yield tensile strength results are as follows: 909 MPa at 20 °C and 731 MPa at 400 °C. The fatigue strength limit is 305 MPa at 20 °C and 214 MPa at 400 °C. The aim of this work was to provide a reliable data base for designers, allowing them to apply NCI for the new generation of piston engines in a more favorable way.