Mechanical properties distributions of PM parts

The final mechanical properties of PM parts are strongly affected by the processing parameters: processing controls porosity, composition, and microstructure. Variations within the processing sequence lead to significant property variations. Variations in strength values are often accounted for by the publication of typical values and minimum values. Other mechanical properties, important for critical applications, such as toughness, are even more sensitive to processing. This paper discusses the use of Weibull statistics to analyse the properties of PM parts and suggest new ways to determine property variability for design application. Examples of different properties and materials are used to illustrate the variation. The effects of processing parameters in controlling the variability are discussed. Weibull parameters are suggested as being more suitable for designers than the current system.