Processing by Additive Manufacturing Based on Plasma Transferred Arc of Hastelloy in Air and Argon Atmosphere

Abstract

This research was carried out to determinate the effect of the atmosphere processing conditions (air and argon) and two specific thermal treatments, on the properties of specimens made from the nickel-based alloy Hastelloy C-22 by plasma transferred arc (PTA). Firstly, the additive manufacturing parameters were optimized. Following, two walls were manufactured in air and argon respectively. Afterwards, a determinate number of specimens were cut out and evaluated. Regarding the comparison performed with the extracted specimens from both walls, three specimens of each wall were studied as-built samples. Furthermore, a commonly used heat treatment in Hastelloy, with two different cooling methods, was selected to carry out additional comparisons. In this respect, six additional specimens of each wall were selected to be heat treated to a temperature of 1120 °C for 20 min. After the heat treatment, three of them were cooled down by rapid air cooling (RAC), while the other three were cooled down by water quenching (WQ). In order to study the influence degree of the processing conditions, and how the thermal treatments could modify the final properties of the produced specimens, a detailed characterization was performed. X-ray diffraction and microstructural analyses revealed the phases-presence and the apparition of precipitates, varying the thermal treatment. Moreover, the results obtained after measuring mechanical and tribological properties showed slight changes caused by the variation of the processing atmosphere. The yield strength of the extracted specimens from the two walls achieved values closer to the standards ones in air 332.32 MPa (±21.36 MPa) and in argon 338.14 MPa (±9 MPa), both without thermal treatment. However, the effect of the cooling rate resulted as less beneficial, as expected, reducing the deformation properties of the specimens below 11%, independently of the air or argon manufacturing atmosphere and the cooling rate procedure.

Development in PTA Surface Modifications – A Review

“…Generally, the main types of material used by plasma transferred arcadditive manufacturing (PTA-AM) are Ni-based alloys (Inconel, Hastelloy). More details about the process parameters and quality of the elements could be found in [82,83]. Moreover, for very precise applications, the micro-PTA additive manufacturing technology is used.…”

Effect of Processing Atmosphere and Secondary Operations on the Mechanical Properties of Additive Manufactured AISI 316L Stainless Steel by Plasma Metal Deposition

“…A commercial AISI 1015 steel plate with dimensions of 200 mm × 200 mm × 10 mm was selected as substrate. As on previous authors' work [9,15], the feasibility of manufacturing the raw material powders by PMD processing was tested by optimizing the following welding parameters: main arc current (A), pilot current (A), welding speed (mm/min), material feeding rate (g/min), pilot gas flow (L/min) and shielding gas flow (L/min). The parameter optimization was carried out in order to avoid cracks, delamination between layers due to a lack of input energy and porosity as a result of gas trapped in the matrix when high energy is used.…”

“…The PMD manufacturing process is a rapidly rising AM technology thanks to its advantages over laser-based AM processes. In this technique, a plasma is used as the energy source to melt the starting materials [9,10]. The plasma spot, larger than the laser spot, presents a high feeding rate (1-10 kg/h) and, as a consequence, a high production rate, which is interesting for today's industrial sector [11,12].…”

Plasma Metal Deposition for Metallic Materials

“…In line, another named classification can be considered according to disposing of the raw material. The material can be injected or introduced directly into the energy source, blown-powder/wire-feed techniques (Direct Metal Deposition, DMD) [3][4][5], or disposed on a bed or platform in powder shape (Laser Powder Bed Fusion, LPBF) [6][7][8]. Such powder-bed based ALM equipment is typically limited in manufacturing large parts due to the size of their building platforms.…”