Abstract:
Several techniques can be used to improve surface properties of metals . These can involve
changes on the surface chemical composition such as alloying or on the surface microstructure
such as hardening or on the burnishing such as improved surface finish ,increased
microhardness ,corrosion resistance and fatigue life as result of the produced compressive
residual stress . In the present work surface was improved (surface roughness) and increased
surface microhardness with a roller burnishing of aluminum alloys 2024,T361 .
Surface roughness characterization was done by an Surtonic3+Instrument ,mechanical features
surface microhardness before, and after internal roller burnishing were evaluated by Vickers
microhardness test ,and microstructure characterization was tested by an optical microscope
,grain size transformations (change microstructure) rapid solidification was then analyzed and
discussed .
This research was aimed to determine the optimal setting of the process parameters on
the internal roller burnishing and effect of working parameters on average roughness , surface
microhardness and microstructure ,the aluminum alloys 2024,T361 was used as a workpiece .
50 diameter model DT5000 adjustment range (-0.2/+0.6mm) produced in north India by
(DYNEMECH SYSTEMS PVT.LTD) was used as the internal roller burnishing tool. The
experiments were done on an CNC milling machine model Bridgeport VMC500 by using
Taguchi methodology .The Taguchi method is used to formulate the experimental layout and
analyze the effect of each parameter on the burnishing characteristics, and to predict the
optimal choice for each burnishing parameter such as burnishing speed, burnishing feed and
tool diameter. Analysis of variance (ANOVA) used F-test to investigate which process
parameters significantly affect the performance characteristics ,and the percent contribution of
these parameters on surface roughness , surface microhardness and microstructure .
In general it is found that the tool diameter mainly affect the surface roughness ,while
the tool diameter and burnishing speed significantly affects the surface microhardness from the
microstructure there is notesable change in the surface integrity reported.
