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

https://docs.lib.purdue.edu/cgi/viewcontent.cgi?article=1037&context=mepubs

Additive manufacturing of Ti6Al4V alloy: A review

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

This article reviews published data on the mechanical properties of additively manufactured metallic materials. The additive manufacturing techniques utilized to generate samples covered in this review include powder bed fusion (e.g., EBM, SLM, DMLS) and directed energy deposition (e.g., LENS, EBF3). Although only a limited number of metallic alloy systems are currently available for additive manufacturing (e.g., Ti-6Al-4V, TiAl, stainless steel, Inconel 625/718, and Al-Si-10Mg), the bulk of the published mechanical properties information has been generated on Ti-6Al-4V. However, summary tables for published mechanical properties and/or key figures are included for each of the alloys listed above, grouped by the additive technique used to generate the data. Published values for mechanical properties obtained from hardness, tension/compression, fracture toughness, fatigue crack growth, and high cycle fatigue are included for as-built, heat-treated, and/or HIP conditions, when available. The effects of test...

Metal Additive Manufacturing: A Review of Mechanical Properties

The effect of laser power and traverse speed on microstructure, porosity, and build height in laser-deposited Ti-6Al-4V

Mold wear during the casting of Ti-6Al-4V in a permanent (steel) mold was investigated using a combination of macro- and micro-scale observations and measurements. For this purpose, a steel mold with interchangeable inserts of three candidate mold steels (H13, P20, and 1040) was used. Inserts were removed at regular intervals during casting under prototype-production conditions and inspected to assess mold wear. Two major mold wear types were identified: soldering and “wrinkling.” Soldering was concluded to be a result of local over-heating of the mold, and wrinkling a result of cyclic stresses caused by a combination of solid-state phase transformations and large temperature gradients. The 1040 inserts performed the best; soldering was less severe and wrinkling did not occur. The better performance of the 1040 inserts was attributed to lower mold temperatures and thermal gradients due to the higher thermal conductivity of 1040 relative to H13 or P20.

P. A. Kobryn

Papers

The effect of laser power and traverse speed on microstructure, porosity, and build height in laser-deposited Ti-6Al-4V

Mold wear during permanent-mold casting of Ti-6Al-4V