Cream as a Composite Material

Many of the mechanical and thermal properties can best be understood by thinking of ice cream as a composite material. The properties of composite materials are generally intermediate between the properties of the individual components. For example, the thermal conductivity of ice cream with 100% overrun is typically 0.3Wm K, which lies between the values for ice (2.2 W m K ), matrix (0.4 W m K ) and 

Modulus of water ices as a function of ice content ( ) and the predictions of the rule of mixtures for continuous and discontinuous ice microstructures (lines) (see text) 

Fracture provides another demonstration of the effect of the microstructure on the macroscopic properties. When a sample is deformed, for example in the three-point bend test, the force increases until a crack forms at the top surface. This crack travels through the ice cream until it reaches the other side, at which point the sample breaks. The crack takes the easiest route, i.e. it goes through the weakest parts of the microstructure. The path that the crack takes therefore depends on the properties and spatial distribution of the components. 

---