Mechanical properties-microstructure relation

Ares, A.E. Caram, R. Schvezov, C.E. (2006) Relation between As-Cast Mechanical Properties, Microstructure and Solidification Conditions for Zn-Al Alloys, Proceedings of MCWASP International Conference Modeling of Casting, Welding and Advance Solidification Processes - XI, Opio, France, June of 2006... 

In order to monitor the mechanical properties in relation to the microstructure, the knowledge of the precipitation state at the end of a thermo-mechanical treatment is of prime importance. In this purpose, Arcelor develops models that allow for the prediction of the influence of the process parameters on the state of precipitation. The model Multipreci, developed at IRSID is one of them. It (Hedicts the precipitation kinetics of mono- and di-atomic particles in ferrite and austenite as a function of the time-temperature history. It is based on the classical theories for diffusive phase transformation and treats simultaneously the nucleation, growth and ripening phenomena. The state of precipitation that is predicted includes the particle size distribution, their number and volume fraction. From these values, the effect of the precipitates on the mechanical properties can be calculated. 

The study of microstructures in relation to important properties of metals and alloys, especially mechanical properties, continues apaee. A good overview of eurrent concerns can be found in a multiauthor volume published in Germany (Anon. 1981), and many chapters in my own book on physieal metallurgy (Cahn 1965) are devoted to the same issues. 

Shermann D, Brandon D (2000) Mechanical Properties and their Relation to Microstructure. In Riedel R (ed) Handbook of Ceramic Hard Materials. Wiley-VCH, Weinheim, p 66... 

Bmnello, N., McGauley, S.E., and Marangoni, A. 2003. Mechanical properties of cocoa butter in relation to its crystallization behavior and microstructure. Lebensm.-Wiss. u.-Technol. 36, 525-532. 

Wotting, G., Kanka, B. and Ziegler, G., (1986), Microstructural development, microstructural characterization and relations to mechanical properties of dense silicon nitride , in Hampshire S, Non-oxide Technical and Engineering Ceramics, London and New York, Elsevier Science, 83-96. 

The mechanical properties of rapidly polymerizing acrylic dispersions, in simulated bioconditions, were directly related to microstructural characteristics. The volume fraction of matrix, the crosslinker volume in the matrix, the particle size distribution of the dispersed phase, and polymeric additives in the matrix or dispersed phase were important microstructural factors. The mechanical properties were most sensitive to volume fraction of crosslinker. Ten percent (vol) of ethylene dimethacrylate produced a significant improvement in flexural strength and impact resistance. Qualitative dynamic impact studies provided some insight into the fracture mechanics of the system. A time scale for the elastic, plastic, and failure phenomena in Izod impact specimens was qualitatively established. The time scale and rate sensitivity of the phenomena were correlated with the fracture surface topography and fracture geometry in impact and flexural samples. 

The next area of future development is microstructure analysis. Although numerous attempts have been made to connect crystal stmcture to food texture, a long road still remains ahead before it can be said that a certain type of stmcture leads definitively to certain mechanical properties. Development of methodologies for structure analysis and further developments in analytical modeling of crystalline microstructure are needed. Further, the connection between these microstructural models and food properties related to the crystalline microstructure are important. 

The challenge for ceramists is to achieve perfect control on related properties. This obviously requires correlating the parameters of the synthesis process with the resulting nano/microstructure. This chapter focuses on the ways to prepare multiphase materials and their main controlling parameters, on the precursors and their structure, and on the porosity, densification, and final mechanical properties. The goal here is not to give a complete overview, but to address the most important points and the ways to solve most of the problems with some examples. Particular attention will be given to nondestructive methods able to characterize the materials over different scales (from atomic distances to full size). 

The mechanical properties of materials can be determined from wave propagation techniques. Thus the responses of composite polymers to mechanical perturbations as well as information on specific problems related to microstructural inhomogeneities can be obtained by using these techniques. 

Hubert, L. David, L. Seguela, R. Vigier, G. Degoulet, C. Germain, Y. Physical and mechanical properties of polyethylene for pipes in relation to molecular architecture. I. Microstructure and crystallisation kinetics. Polymer 2001, 42, 8425-8434. 

The titanium-based composites with discontinuous reinforcement are attractive materials for a wide range of applications because of their high specific strength and stiffness and good fracture-related properties. Mechanical behavior of these materials depends strongly on both composition and microstructure of matrix and type, size and volume fraction of reinforcing phase. Hot plastic deformation is a powerful tool enhancing mechanical properties of titanium alloys. 

Collins has reported the synthesis of a related class of metallocenes (43), some of which form elastomeric, stereoblock polypropylene when activated by The elastomeric properties of the polymer formed using 43 (M = Hf, X = SiMe2 7)xn = 25 °C) were far superior to those formed by the other metallocenes in the study. The polymers made using 42 and 43 have similar microstructures, as well as physical and mechanical properties. However, after detailed microstructural analysis of the polymer the authors proposed an alternate mechanism of stereocontrol to Chien s site epimerization model (Scheme... 

---