Metallic Alloys

Alloy

A metallic material composed of two or more elements and designed to obtain a useful combination of properties.

Metal Alloys in Additive Manufacturing

More than 100 different alloys are commercially available or have been demonstrated in laboratories as suitable for additive manufacturing, covering the primary alloy classes.

Reason why alloy is utilized in AM

Using alloys with known chemistry and characteristics reduces the risk of unforeseen metallurgical problems, and existing alloys already have established material supply chains.

Conventional Origins of Many AM Alloys

Many alloys currently used in additive manufacturing were originally developed for casting, welding, or wrought processes such as sheet production, plate production, forging, and extrusion.

brittleness, corrosion issues

Using an alloy with known chemistry and characteristics reduces the risk of unforeseen metallurgical problems such as ___________ or ________________.

Alloy Supply Chain

A system for producing and supplying an alloy in usable feedstock forms; established alloys are advantageous in AM because many are already available as powder, wire, or foil for other markets.

Alloy Characterization

Alloys are commonly characterized by properties such as composition, density, and mechanical properties; weldability and heat-treatment requirements are additionally important considerations for additive manufacturing.

Weldability

The ability of a material to undergo welding successfully; it is particularly important in additive manufacturing processes that melt and fuse material.

Many fusion-based AM processes melt an alloy and fuse it to previously deposited layers through solidification, making the alloy's welding behavior important.

Why is weldability important in fusion-based additive manufacturing?

Fusion-Based Additive Manufacturing

Additive manufacturing in which material is melted and fused to previously deposited material through solidification.

Each deposited region is melted and fused to previously deposited material through solidification, resembling repeated small-scale welding operations.

Why are fusion-based AM processes sometimes described as micro-welding?

Heat Treatment

Controlled heating and cooling of a material to modify its condition and obtain desired material properties.

thermal treatments

Certain alloys require specific ________________ to obtain optimum properties after additive manufacturing.

Yes, it is true

Is it true that most AM alloys were originally developed for casting, wrought, or welding applications, so the heat treatment optimized for those processing histories may not be optimal for the same alloy produced by additive manufacturing, therefore they would require a different heat treatment here inside the AM?

Processing History

The sequence of manufacturing and thermal processes experienced by a material, which can influence its resulting material condition and properties.

Processing–Structure–Property Relationship

The materials-engineering principle that processing influences material structure, and material structure in turn influences resulting properties.