Quantitative characterization of spatial arrangement of shrinkage and gas (air) pores in cast magnesium alloys

Pressure die-cast magnesium (Mg) alloys contain both shrinkage and gas (air ) microporosity. Characterization of shrinkage and (gas) air microporosity is essential for understanding microstructure-properties correlations in th ese alloys. In this contribution, a recently reported digital image analysi s (DIA) technique has been further developed to separately quantify and cha racterize the attributes of shrinkage and air microporosity in AM series of cast Mg alloys. The image analysis procedure is utilized to measure the ne arest-neighbor distributions of the shrinkage and gas (air) pores, and to q uantify the clustering tendency of the pores. A new affinity parameter is d efined to characterize the affinity of gas (air) pores to shrinkage pores a nd vice versa. The affinity parameters are computed from the same image ana lysis data. (C) 2001 Elsevier Science Inc. All rights reserved.