Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Diffusion


Taguchi Approach to Optimize Pack Aluminization Parameters in Carbon Steel Using MINITAB13

Abbas Khammas Hussein

Engineering and Technology Journal, 2009, Volume 27, Issue 11, Pages 2259-2272

Pack aluminization has been rapidly developed and widely used in many fields
due to its superior properties of coating. Surface is the only part of the component
which has to coexist with external environment. Majority of engineering failures
originate from the surfaces and components degrade in service leading to failures such
as fatigue, wear, corrosion and oxidation. The present study deals with the surface
modification of steel base through diffusion of aluminium by aluminium pack
cementation for improving wear and corrosion resistance. The material chosen for
study is medium carbon steel. Effect of varying weight percentage (wt.%) of halide
activator (NH4Cl) at different diffusion temperatures and times on the microstructure
and microhardness of aluminized specimens was studied. Taguchi robust design
technique using MINITAB13 was used to rank several factors that may affect the
microhardness and microstructure in order to formulate the optimum conditions. The
Taguchi orthogonal array L9 (33) was used for experimental design with three level of
consideration for each factor. The respone (Microhardness) was analyzed based on the
Taguchi’s signal-to-noise ratio. The use of 4%wt. of (NH4Cl) at 5hr and diffusion
temperature of 700oC seems to be the optimum condition, where the surface hardness
could be increased to 1000Hv when aluminized. X-Ray diffraction studies have been
confirmed the presence of aluminides in the surface layer, which could be instrumental
in the significant increase in the surface hardness.

Study Diffusion of Water to Carbon Fiber /Epoxy Composite

Adnan A. Abdul Razak

Engineering and Technology Journal, 2009, Volume 27, Issue 1, Pages 172-181

In present work moisture diffusion properties of the woven fabric carbon/epoxy
laminates were determined using weight gain, experiments over a temperature range of
30 0C to 60 0C. The laminate–shaped fiber reinforced composites were manufactured by
using epoxy resin (Epon 828) cured with TETA (tri ethylene tetra amine) reinforced with
carbon fiber. The prepared Composite samples were immersed in water for several
weeks and moisture content was measured. The diffusivity of the composite was found
to obey the Arrhenius relation over the entire range of temperature. Analytical solution to
Fick’s law is done by build up computer program in Matlab. Good agreement between
experiment data and analytical solution of Fick’s Law.