Surface mechanical attrition treatment

Arifvianto, B., Suyimo, M., Mahardika, M., Dewo, R, Iswanto, P.T., Salim, UA., 2011. Effect of surface mechanical attrition treatments (SMAT) on microhardness, surface roughness, and wettability of AISI 316L. Mater. Chem. Phys. 125, 418-426. 

Electrochemical corrosion resistance of a NC surface of 316 stainless steel developed by surface mechanical attrition treatment was found to be considerably inferior to the MC unmodified bulk. This behaviour is attributed to the considerable increase in the fast diffusion channels for ions, i.e. grain boimdaries and triple junctions in the NC material. In another study, the grain refinement of stainless steels to a nanometric level is reported to improve the corrosion resistance, as suggested by the considerably extended passivation for NC in the polarisation plots. The authors have attributed this behaviour to the greater chromium diffusion in the NC structure, which may be argued given the very low diffusivity (i.e. 10 -10 s ) at ambient temperatures. 

Chakravarty D, Sarada BV, Chandrasekhar SB, Saravanan K, Rao TN (2011) A novel method of fabricating porous silicon. Mater Sci Eng A 528 7831-7834 Christophersen M, Merz P, Quenzer J, Carstensen J, Foil H (2001) Deep electrochemical trench etching with organic hydrofluoric electrolytes. Sens Actuator A 88 241-246 Coblenz WS (1990) The physics and chemistry of the sintering of silicon. J Mater Sci 25 2754-2764 De Castro CL, Mitchell BS (2002) Nanoparticles from mechanical attrition. In Baraton M-I (ed) Synthesis, functionalization and surface treatment of nanoparticles. American Scientific Publisher, Stevenson Ranch... 

Castro, C.L., Mitchell, B.S. Nanoparticles from mechanical attrition. In Baraton M.I. (ed.) Synthesis, Functionalization and Surface Treatment of Nanopatticles, pp. 1-15. American Scientific Publishers, Stevenson Ranch (2002)... 

Activated Carbon (AC) is frequently used as a support in heterogeneous catalysis. It is attractive due to inertness of carbon in acidic and basic environments, and because precious metals, such as platinum, can easily be reclaimed by combustion of the carbon. AC is generally prodnced from naturally occiming caibon sources, such as nutshells, wood or peat. By pyrolysis in the absence of air or treatment with steam a carbon snpport of a high specific surface area is obtained. However, with AC it is difficult to produce bodies of a desired size distribution that are mechanically strong and thus attrition resistant. Also the pore structure and the surface characteristics (hydrophilic vs. hydrophobic) are difficult to control. 

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