Understanding the Mechanical Response of Friction Stir Welded …
45
were used to obtain the microhardness profile based on thermal history of the
heat-treated samples.
(c) Venkateswarlu and co-workers [14] studied the outcome of tool design on
both mechanical properties and metallurgical characteristics of the friction stir
welded plates of aluminum alloy 7039. The effectiveness of both modeling and
tool design was revealed for predicting the optimum weld characteristics based
on different parameters specific to tool geometry. Pin diameter was observed to
be the most remarkable factor while shoulder diameter was the least contributing
factor for controlling the tensile properties of the welded joint. Surface response
regression equations were used to both verify and validate adequacy of the
proposed model and an overall accuracy in prediction for the different tool
geometries.
(d) Salih and co-workers [15] discussed overall critical issues spanning cost reduction, high production efficiency and an improvement in the joint efficiency that
establishes the current state of the art for the joining of aluminum alloy-based
MMCs using the technique of friction stir welding. Looking at the gap area, an
emphasis was also made to study using a systematic approach, which will help in
establishing the effect of both percentage and type of reinforcement on overall
efficiency of the welded joints. An urgent need to study composite materials
other than monolithic alloys of aluminum was ruled out, which can possibly
become a viable candidate material for selection and use in automobile, ground
transportation, and aerospace-related applications.
(e) Kumar and co-workers [16] describe the impact of both process variables and
tool geometry on friction stir welding of in situ hot rolled TiC/Al-4.5Cu metal
matrix composites. Varying shoulder geometry of a hardened bimetallic tool
was used with variable process parameters to study the effect on both mechanical properties and metallurgical characteristics. Scanning electron microscopy
(SEM) observations reveal an overall refinement in the grain structure of the
matrix alloy and a redistribution of the reinforcing particles in the nugget zone.
X-ray diffraction analysis revealed an indication of the presence of both CuAl 2
and CuAl 2 O 4 in the stir zone. Fractography observations revealed a predominantly dimple fracture, which clearly reveals the ductile nature of failure of the
weld samples. Multiple regression equations were used to predict the impact of
input variables and the observed errors were taken into account.
(f) Yigezu and co-workers [17] examined the various process parameters used in
friction stir welding of hot rolled 10TiC/Al-12Si in situ composite by use of a
flame hardened bimetallic tool equipped with a titanium alloy probe. The tool
variant and rotational speed were found to be the two most influential welding
parameters for obtaining a sound welded joint using full factorial design of
the experiments. To determine both the significance and impact of the desired
optimized outputs, a multi-response desirability function technique was implemented. The optimization technique was adopted to check for the presence of
errors in the optimality test, which was in the range of 0.07–2.98%. However,
45
were used to obtain the microhardness profile based on thermal history of the
heat-treated samples.
(c) Venkateswarlu and co-workers [14] studied the outcome of tool design on
both mechanical properties and metallurgical characteristics of the friction stir
welded plates of aluminum alloy 7039. The effectiveness of both modeling and
tool design was revealed for predicting the optimum weld characteristics based
on different parameters specific to tool geometry. Pin diameter was observed to
be the most remarkable factor while shoulder diameter was the least contributing
factor for controlling the tensile properties of the welded joint. Surface response
regression equations were used to both verify and validate adequacy of the
proposed model and an overall accuracy in prediction for the different tool
geometries.
(d) Salih and co-workers [15] discussed overall critical issues spanning cost reduction, high production efficiency and an improvement in the joint efficiency that
establishes the current state of the art for the joining of aluminum alloy-based
MMCs using the technique of friction stir welding. Looking at the gap area, an
emphasis was also made to study using a systematic approach, which will help in
establishing the effect of both percentage and type of reinforcement on overall
efficiency of the welded joints. An urgent need to study composite materials
other than monolithic alloys of aluminum was ruled out, which can possibly
become a viable candidate material for selection and use in automobile, ground
transportation, and aerospace-related applications.
(e) Kumar and co-workers [16] describe the impact of both process variables and
tool geometry on friction stir welding of in situ hot rolled TiC/Al-4.5Cu metal
matrix composites. Varying shoulder geometry of a hardened bimetallic tool
was used with variable process parameters to study the effect on both mechanical properties and metallurgical characteristics. Scanning electron microscopy
(SEM) observations reveal an overall refinement in the grain structure of the
matrix alloy and a redistribution of the reinforcing particles in the nugget zone.
X-ray diffraction analysis revealed an indication of the presence of both CuAl 2
and CuAl 2 O 4 in the stir zone. Fractography observations revealed a predominantly dimple fracture, which clearly reveals the ductile nature of failure of the
weld samples. Multiple regression equations were used to predict the impact of
input variables and the observed errors were taken into account.
(f) Yigezu and co-workers [17] examined the various process parameters used in
friction stir welding of hot rolled 10TiC/Al-12Si in situ composite by use of a
flame hardened bimetallic tool equipped with a titanium alloy probe. The tool
variant and rotational speed were found to be the two most influential welding
parameters for obtaining a sound welded joint using full factorial design of
the experiments. To determine both the significance and impact of the desired
optimized outputs, a multi-response desirability function technique was implemented. The optimization technique was adopted to check for the presence of
errors in the optimality test, which was in the range of 0.07–2.98%. However,