This article series explores the indispensable role of characterization in the development of cold spray coatings and illustrates some of the common processes used during coating development.

Process optimization and optimal component performance can be achieved when multiple variables are measured and studied as a whole. In the investigation described in this article, fatigue performance of AISI 8620 H steel was characterized as a function of carburization case depth, hardness, residual stress, and retained austenite to demonstrate that an optimized carburization process could be engineered to meet specific application requirements.

Aluminum components with refined microstructures produced by high pressure die casting enable manufacturers to gain energy savings via shorter production cycles—if casting and tempering parameters are optimized. This article reports on research results indicating it is possible to increase hardness of hypereutectic Al-Si alloys by optimizing the water quenching rate and duration of room temperature hold, and producing castings with finer microstructures.

This article describes how shielding gas composition, either argon or nitrogen, affects the hardness, tensile strength, and toughness of high-power, high-brightness laser welds made on various base materials, including A508 forging steel, 316L stainless steel, Inconel 690, and solution-annealed IN718.

Research conducted at a brass-strip plant in Zutphen, Netherlands shows how nonlinear modeling can be used to predict the grain size and hardness of annealed strip based on composition and process variables. Production data gathered over the course of a year were used to train a feed-forward neural network that achieved a correlation coefficient of more than 86% when presented with new input data. The standard deviation between predicted and measured grain size was about 4.2 µm.

This article reviews the measurement physics of macro and micro Vickers indentation testing and the factors that determine measurement precision and repeatability. Study results show that when force loads of less than 100 gf are used, it is difficult for operators to precisely determine the position of the indenter tip, leading to various measurement errors. These errors explain the data anomalies reported in the literature for low-load Vickers hardness testing, which are often incorrectly attributed to material characteristics.

This article evaluates the sliding wear behavior of fiber-reinforced 7075 Al alloy composites. It explains how the composite samples were made and shows how different fiber materials, volume percentages, and orientations affect hardness and wear resistance. It also interprets wear test results and what they reveal about wear mechanisms in metal-matrix composites.