Additive manufacturing of metallic components – Process, structure and properties

Additive manufacturing (AM), widely known as 3D printing, is a method of manufacturing that forms parts from powder, wire or sheets in a process that proceeds layer by layer. Many techniques (using many different names) have been developed to accomplish this via melting or solid-state joining. In this review, these techniques for producing metal parts are explored, with a focus on the science of metal AM: processing defects, heat transfer, solidification, solid-state precipitation, mechanical properties and post-processing metallurgy. The various metal AM techniques are compared, with analysis of the strengths and limitations of each. Only a few alloys have been developed for commercial production, but recent efforts are presented as a path for the ongoing development of new materials for AM processes.

The metallurgy and processing science of metal additive manufacturing

A review on selective laser sintering/melting (SLS/SLM) of aluminium alloy powders: Processing, microstructure, and properties

Welding Metallurgy of

Preface. 1. Introduction. 1.1 Ni-base Alloy Classification. 1.2 History of Nickel and Ni-base Alloys. 1.3 Corrosion Resistance. 1.4 Nickel Alloy Production. 2. Alloying Additions, Phase Diagrams, and Phase Stability. 2.1 Introduction. 2.2 General Influence of Alloying Additions. 2.3 Phase Diagrams for Solid-Solution Alloys. 2.4 Phase Diagrams for Precipitation Hardened Alloys--gamma' Formers. 2.5 Phase Diagrams for Precipitation-Hardened Alloys--gamma" Formers. 2.6 Calculated Phase Stability Diagrams. 2.7 PHACOMP Phase Stability Calculations. 3. Solid-Solution Strengthened Ni-base Alloys. 3.1 Standard Alloys and Consumables. 3.2 Physical Metallurgy and Mechanical Properties. 3.3 Welding Metallurgy. 3.4 Mechanical Properties of Weldments. 3.5 Weldability. 3.6 Corrosion Resistance. 3.7 Case Studies. 4. Precipitation Strengthened Ni-base Alloys. 4.1 Standard Alloys and Consumables. 4.2 Physical Metallurgy and Mechanical Properties. 4.3 Welding Metallurgy. 4.4 Mechanical Properties of Weldments. 4.5 Weldability. 5. Oxide Dispersion Strengthened Alloys and Nickel Aluminides. 5.1 Oxide Dispersion Strengthened Alloys. 5.2 Nickel Aluminide Alloys. 6. Repair Welding of Ni-base Alloys. 6.1 Solid-Solution Strengthened Alloys. 6.2 Precipitation Strengthened Alloys. 6.3 Single Crystal Superalloys. 7. Dissimilar Welding. 7.1 Application of Dissimilar Welds. 7.2 Influence of Process Parameters on Fusion Zone Composition. 7.3 Carbon, Low Alloys and Stainless Steels. 7.4 Postweld Heat Treatment Cracking in Stainless Steels Welded with Ni-base Filler Metals. 7.5 Super Austenitic Stainless Steels. 7.6 Dissimilar Welds in Ni-base Alloys - Effect on Corrosion Resistance. 7.7 9%Ni Steels. 7.8 Super Duplex Stainless Steels. 7.9 Case Studies. 8. Weldability Testing. 8.1 Introduction. 8.2 The Varestraint Test. 8.3 Modified Cast Pin Tear Test. 8.4 The Sigmajig Test. 8.5 The Hot Ductility Test. 8.6 The Strain-to-Fracture Test. 8.7 Other Weldability Tests. Appendix A Composition of Wrought and Cast Nickel-Base Alloys. Appendix B Composition of Nickel and Nickel Alloy Consumables. Appendix C Corrosion Acceptance Testing Methods. Appendix D Etching Techniques for Ni-base Alloys and Welds. Author Index. Subject Index.

Welding Metallurgy and Weldability of Nickel-Base Alloys

Preface 1 Introduction 2 Phase Diagrams 3 Alloying Elements and Constitution Diagrams 4 Martensitic Stainless Steels 5 Ferritic Stainless Steels 6 Austenitic Stainless Steels 7 Duplex Stainless Steels 8 Precipitation-Hardening Stainless Steels 9 Dissimilar Welding of Stainless Steels 10 Weldability Testing Appendix 1: Nominal Compositions of Stainless Steels Appendix 2: Etching Techniques for Stainless Steel Welds Author Index Subject Index

Welding Metallurgy and Weldability of Stainless Steels

Welding Metallurgy and Weldability

A detailed investigation of the early stages of secondary austenite precipitation in five duplex stainless steel (DSS) commercial alloys (UNS S32304, S32205, S32550, S32750, and S32760) has been conducted using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Based on this study, a model is proposed that describes the interaction betwee Cr2N and austenite (intergranular and intragranular) precipitation in these alloys. Depending on nitrogen availability and interface mobility, Cr2N precipitation along existing ferrire/austenite interfaces precedes intergranular secondary austenite growth. The low-energy interfaces formed between the Cr2N, the ferrite, and the austenite, along with the coupled diffusion processes, are the factors controlling this phase transformation. Finally, in the case of the intragranular nitrides, a mechanism is proposed whereby the nitrides serve as sites for heterogeneous nucleation of intragranular secondary austenite.

John C. Lippold

Papers

Welding Metallurgy and Weldability of Stainless Steels

Welding Metallurgy and Weldability of Nickel-Base Alloys

Welding Metallurgy and Weldability

The relationship between chromium nitride and secondary austenite precipitation in duplex stainless steels

Dissimilar friction welding of 6061-T6 aluminum and AISI 1018 steel: Properties and microstructural characterization