A brief survey of sensing for metal-based powder bed fusion additive manufacturing

Abstract

Purpose -Powder bed fusion additive manufacturing (PBFAM) of metal components has attracted much attention, but the inability to quickly and easily ensure quality has limited its industrial use. Since the technology is currently being investigated for critical engineered components and is largely considered unsuitable for high volume production, traditional statistical quality control methods cannot be readily applied. An alternative strategy for quality control is to monitor the build in real time with a variety of sensing methods and, when possible, to correct any defects as they occur. This article reviews the cause of common defects in powder bed additive manufacturing, briefly surveys process monitoring strategies in the literature, and summarizes recently-developed strategies to monitor part quality during the build process. Design/methodology/approach -Factors that affect part quality in powder bed additive manufacturing are categorized as those influenced by machine variables and those affected by other build attributes. Within each category, multiple process monitoring methods are presented. Findings -A multitude of factors contribute to the overall quality of a part built using PBFAM. Rather than limiting processing to a pre-defined build recipe and assuming complete repeatability, part quality will be ensured by monitoring the process as it occurs and, when possible, altering the process conditions or build plan in real-time. Recent work shows promise in this area and brings us closer to the goal of wide-spread adoption of additive manufacturing technology. Originality/value -This work serves to introduce and define the possible sources of defects and errors in metal-based PBFAM, and surveys sensing and control methods which have recently been investigated to increase overall part quality. Emphasis has been placed on novel developments in the field and their contribution to the understanding of the additive manufacturing process.

The influence of material properties and process parameters on the spreading process in additive manufacturing

“…Particle drag during the spreading process was also reported experimentally by Foster et al [38] and Abdelrahman et al [39].…”

Sensor-Based Build Condition Monitoring in Laser Powder Bed Fusion Additive Manufacturing Process Using a Spectral Graph Theoretic Approach

“…Objective 1: Develop and apply a spectral graph theoretic approach to monitor the build condition in LPBF from the data gathered by the aforementioned three sensors. The intent is to detect the onset of deleterious phenomena such as unexpected variations in the thermal history (cooling rate) which would lead to inconsistent properties [13][14][15]. In the worst case, these may ultimately result in build failures.…”

“…Tapia and Elwany [40] have conducted a comprehensive review of sensor-based process monitoring approaches, specifically focused on metal AM processes. More recently, Foster et al [15], Purtonen et al [41], Mani et al [22], Everton et al [42], and Grasso and Colosimo [4] provided excellent reviews of the status quo of sensing and monitoring focused in metal AM. However, there is a persistent gap in analytical approaches to synthesize this data and extract patterns that correlate with specific process conditions (build status) and defects [43].…”

Repeatability in Performance of Micro Cooling Geometries Manufactured with Laser Powder Bed Fusion

“…Bauza et al 19 noted that the dimensional errors were generally repeatable across builds, alluding to the fact that tuning build parameters could minimize these errors. However, tuning build parameters for every part would require repeated builds and in-depth analysis of the results of those builds, as well as in situ monitoring of the build process 22 , which may be time and cost prohibitive.…”