Influence of Processing Conditions on the Mechanical Properties of 17-4PH Specimens Produced by Additive Manufacturing

Abstract

The purpose of this research is to study the influence of the processing conditions that affect the final behaviour of specimens made from a 17-4PH composition powder without the necessary thermal treatment to be considered 17-4PH, which is manufactured using the additive technique known as plasma metal deposition (PMD). To that end, two walls manufactured from the prealloyed powder were built under two distinct atmospheric conditions, i.e., air and argon, with previously optimized manufacturing parameters. The additional effect of two applied thermal treatments (TT) was studied by means of property and microstructural analyses of the extracted specimens from each consolidated wall. The two thermal treatments consisted of a heating rate of 10 ◦C/min to 482 ◦C (TT1) and 620 ◦C (TT2), with the temperatures for 1 and 4 h, respectively; the cooling rate was 5 ◦C/min for both treatments. According to the findings, the presence of an argon atmosphere during manufacturing promoted the presence of an austenite phase, reducing the deformation of the samples and enhancing their Young’s modulus. The TT1 treatment positively contributed, improving the mechanical properties in general, and TT2 substantially improved the elongation in both sets of specimens.