This article focuses on a study that was performed to understand the effects of powder attributes; process parameters; and hot isostatic pressing (HIP) treatment on the densification, mechanical and corrosion properties, and microstructures of 17-4 PH stainless steel gas- and water-atomized laser-powder bed fusion (LPBF) parts at various energy densities. The results from the study showed the strong dependence of densification, mechanical properties, and microstructures on temperature, pressure, and time during the HIP cycle. The density, ultimate tensile strength, hardness and yield strength of gas and water-atomized LPBF parts increased due to HIP treatment and were higher than as-printed properties. The results also confirmed superior corrosion performance of the HIP treated LPBF parts.

Part quality in additive manufacturing (AM) is highly dependent on process control, but there is a lack of adequate AM control methods and standards. Laser powder-bed fusion (L-PBF) is one of the most-used metal AM techniques. This article focuses on the following laser control parameters: laser focus, laser power, laser position, and laser power-position synchronization. It then provides a discussion on laser scan strategies. The article also provides an overview of the AM control framework, the two major sections of which are software and hardware.

High-volume additive manufacturing (AM) for structural automotive applications, along the lines of economically viable technologies such as powder metallurgy, castings, and stampings, remains a lofty goal that must be realized to obtain the well-known advantages of AM. This article presents two key opportunities for AM related to automotive applications, specifically within the realm of metal laser powder-bed fusion: alloys and product designs capable of high throughput. The article also presents the general methodology of alloy development for automotive AM. It provides examples of unique designs for reciprocating components in elevated-temperature applications that are also exposed to demanding tribological conditions. The article also discusses the future of AM for automotive applications.

Fatigue failure is a critical performance metric for additively manufactured (AM) metal parts, especially those intended for safety-critical structural applications (i.e., applications where part failure causes system failure and injury to users). This article discusses some of the common defects that occur in laser powder bed fusion (L-PBF) components, mitigation strategies, and their impact on fatigue failure. It summarizes the fatigue properties of three commonly studied structural alloys, namely aluminum alloy, titanium alloy, and nickel-base superalloy.