Rapid solidification and Additive manufacturing

AMPL is part of the NSERC/CFI Holistic Innovation in Additive Manufacturing (HI-AM) Network

1. Microstructural investigation of rapidly solidified droplets of Al-Cu-Sc and Al-Si-Sc

Researchers: Abdoul-Aziz Bogno, Jonas Valloton, Akankshya Sahoo, Mark Gallerneault, and Hani Henein

Funding: NSERC

Status: in progress

Mechanical properties of industrial products are highly influenced by their solidification microstructures. Variation of solidification conditions (such as undercooling or cooling rate) gives possible control of size and morphology of the microstructure, which may substantially influence physical and chemical properties of alloys. High undercooling of alloys below the equilibrium liquidus and eutectics results in rapid solidification and yields materials with improves mechanical properties [1]. Rapid solidification resulting in reduced microsegregation is quite often accompanied by the formation of a broad range of metastable microstructures and structurally different phases. Solidification rate and undercooling can be increased through different techniques including Impulse Atomization (IA) or spray deposition which refer to the disintegration of a bulk liquid material into droplets in a spray chamber filled with gas. The resulting atomized droplets experience a rapid cooling before being solidified into powders (IA) [2] or solidify as a strip form after landing on a substrate [3]. Aluminum alloys are widely used in the automotive and aerospace industries because of their high strength to weight ratio. The development of aluminum alloys with increased strength and ductility is an ongoing challenge for automotive and aerospace applications [4]. Addition of Scandium in Al-alloys promotes age hardening through the precipitation of finely dispersed Al3Sc particles that can tightly pin up the grain boundaries and dislocations. Also Sc addition is found to yield good grain refining in binary aluminum alloys [5]. The strengthening potential for Sc in Al alloys can significantly be improved by increasing the undercooling through rapid cooling which extends the solid solubility of Sc and permitting an increased amount of the Al3Sc strengthening phase on subsequent heat treatments.

In this project rapidly solidified droplets and spray formed Al-4.5wt% Cu and Al-10wt%Si with different Sc additions (in wt%) of 0, 0.1, 0.2 and 0.4 will be generated by Impulse Atomization (IA) in Argon and Helium [6]. The effect of different amounts of Scandium addition to the microstructure and mechanical properties of the atomized droplets will be investigated. Microstructural analyses of the samples will be carried out using Differential Scanning Calorimetry (DSC), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray spectroscopy (EDX), and Electron Microprobe as well as Micro Vickers Hardness tests. In addition, Neutrons Diffraction (ND) and micro-tomography analyses will be done on the samples.

1. Fleming, M. C., Solidification Processing. (McGraw-Hill, London, 1974)

2. Henein, H, Materials Science and Engineering A326 (2002) 92–100

3. N. Ellendt et al, Materials Science and Engineering A 383 (2004) 107–113

4. M. Gallerneault, Novelis Inc., private communications, April 2010

5. K.T. Conlon, et al, Metallurgical and Materials Transactions A, Vol 31A (2000) 240

6. A. Prasad: PhD Thesis, University of Alberta (2006)

2. Microstructural investigation of rapidly solidified droplets of Al-Ce

Researchers: Akankshya Sahoo, Jonas Valloton and Hani Henein

Funding: Equispheres

Status: in progress

Al-Ce based alloys, which consist primarily of fcc aluminum and Al11Ce3, remain thermodynamically stable and retain their mechanical properties at high temperatures. This is due to the near zero solubility of cerium in fcc aluminum, i.e. less than 0.005 wt% at the eutectic temperature. This is orders of magnitude lower than even Sc, which currently leads to some of the most competitive high-temperature alloys (0.2 wt% Sc solubility at 600°C). Thus, the strengthening Al11Ce3 intermetallic is far more stable against high temperature dissolution than precipitates in typical Al-alloys. Additionally, while cerium is the most abundant of the rare earth elements (as abundant as copper), it does not have any significant high-volume applications. As a result, it is considered a by-product of rare earth mining and is so far relatively inexpensive as an alloying element. This project aims at developing an understanding and quantify the role of undercooling, cooling rate, and cooling conditions in the rapid solidification of Al-Ce alloys. To do so, Al-Ce particles will be atomized and fully characterized (microstructure and mechanical properties), as-atomized and after heat treatment.

3. Wear and corrosion performance of modified Ni- and steel-based WC metal matrix composite overlays for use in severe wear applications

Researchers: Dylan Rose, Anne McDonald, Geoffrey Bonias, Nasim Navid Moghadam, Remy Samson, Tonya Wolfe, Shiyu XXXXXX, Ahmed Qureshi, Xingyu Li, Matthew Taylor and Hani Henein

Funding: Syncrude and NSERC-HI-AM, Alberta Innovates

Status: in progress

The aggressive conditions found in the oil sands mining process results in severe wear of mining equipment. To extend component life, protective overlays are applied to standard mining equipment and piping systems. The choice of overlay depends on service environment and economic factors. Tungsten carbide overlays are applied to the most critical components, typically by plasma transferred arc welding (PTA-W) and wire arc additive manufacturing (WAAM). The advantages of coupling a new overlay deposition system, Reactive Plasma Transferred Arc Welding (R-PTAW), with a chemically enhanced Ni- or steel-based WC overlay, are explored. Elemental tungsten and (V,W)C particles are added to a variety of Ni- and steel-based powders, with and without the addition of WC reinforcement particles. Using this novel process, unique composites are formed due to the in-situ formation of precipitates.

4. Fused Deposition Modeling

Researchers: Janmejay Rao, Adam Lim, Marcelino Da Silva Dias Filho, Ahmed Qureshi and Hani Henein

Funding: Syncrude, Saturn Machines and NSERC

Status: in progress

Fused Filament Fabrication (FFF) is gaining interest in Additive Manufacturing of components. While it has largely grown based on the use of polymers, the feasibility to incorporate other classes of materials is an attractive option. When metals are incorporated into the polymer, FFF provides the opportunity to retain the fine structure of the rapidly solidified powder. In order to take full advantage of FFF for application in the resource sector, it is desired to mix both metallic and ceramic powders into a polymer filament. Using FFF, complex additive manufactured composite parts are created for use in wear resistant applications. This method of manufacturing is suitable for use in the oil and gas industry as it has potential to reduce maintenance cost and time, while increasing on-site part production and repair capabilities.

5. Ultrasonically Assisted Atomization

Researchers: Lucas Martin Ishida, Marcelino Da Silva Dias Filho and Hani Henein

Funding: NSERC - HI-AM

Status: in progress

6. Eutectic work

Researchers: Jonas Valloton and Hani Henein

Funding: NSERC - HI-AM

Status: in progress

7. Processing and performance of lattice composites (P2LaC)

Researchers: Yifan Li, Ahmed Qureshi, Marcelino Da Silva Dias Filho and Hani Henein

Funding: Syncrude and NSERC

Status: proposed

The goal of this partnership is to generate new knowledge on the processing, microstructure and properties of a bi-metal casting and metal-metal matrix composite (MMC) castings. The stress field experienced by a 3D component processed for Castings and Additive Manufacturing (AM) of lattice structures will be evaluated using Finite Element Modelling (FEM). Manufacturing of the castings with 3D lattice structures provides freedom of design and manufacture of complex parts. The research will be carried out in three phases. Phase 1 (years 1 and 2) will be the processing of laboratory samples of cylinders composed of a bi-metallic part, and a metallic part joined to an MMC. The mechanical properties of both systems will be evaluated. In Phase 2 (years 1 to 4), different lattice structural architectures will be evaluated using FEM. The most promising structure from FEM results will be compared with built lattices in Phase 3. Phase 3 (years 2 to 4) will address the filling of the candidate lattice and alloy with varying compositions: Cr-white iron and carbon steel, and NiBSi with WC composite and carbon steel. Subsequent evaluation of fill density, microstructure, and wear will be carried out. A foundry (TBD) will be used to make test components and samples. This will be followed by microstructural characterization of the component and field testing by the Partner. For HQP, two graduate students will be recruited for teh project and partial time of one PDF and a Research Associate will contribtue. The graduate studetns will be recruited from a wide pool of potential applicants in order to ensure inclusivity and diversity of the recruited population.

8. Multi Material Robotic Hybrid Additive Wire Arc Manufacturing for Energy Industry

Researchers: Remy Samson, Ahmed Qureshi and Hani Henein

Funding: Syncrude and NSERC

Status: proposed