OCTOBER 19-20, 2012 - YMCA University of Science & Technology

Proceedings of the National Conference on
Trends and Advances in Mechanical Engineering,
YMCA University of Science & Technology, Faridabad, Haryana, Oct 19-20, 2012
Fig 1 A setup of friction welding [8]
5. Influence of process parameters
The important parameters associated with friction welding are 1) Rotational speed 2) Friction pressure 3)
Friction time. High axial pressure and low rotational speed produces a high rate of deformation and this results in
a short weld time. Low friction pressure or high rotational speed produces a relatively low rate of deformation.
The friction time is selected so as to ensure that the faying surfaces are cleaned by friction and the weld zone.
The optimum friction time for a given combination depends on material composition, dimensions, friction
pressure and rotational speed. When the friction time is too short, the heating effect could become irregular and
this results in lower bonding strength in some regions. Any heating time in excess of the optimum time will
reduce productivity and increases material consumption which leads to coarse grain structure.
6. Literature review
Electric-resistance-heat-aided friction welding (ERHAFW) [1] was introduced by Wen-Ya Li, Min Yu. This
technique is a combination of electric resistance welding with the conventional continuous-drive friction welding
and this employment helped in improving the joint quality and energy-saving. In this work, 21-4N (austenitic
stainless steel) and 4Cr9Si2 (martensitic stainless steel) valve steel rods of 4 mm diameter were used as base
metals. The results show that electric-resistance-heat-aided friction welding can be applied to join thin rods
within a relatively short time, which is very difficult for conventional friction welding (FW). The ERHAFW is
suitable for joining the thin rods of 4 mm diameter.
Experimental investigations on joint properties of brass plates by friction stir welding [2] was studied by Cemal
Meran. It is difficult to fusion welding of brasses. The main problem of these alloys in fusion welding is the
evaporation of the zinc during the welding process. The solution to this problem as investigated by him, lies in
recent methodology of friction stir welding. In this research, it was pointed out friction stir welding is capable of
especially brass plates which are 3 mm in thickness. He concluded that evaporation of zinc and copper which
makes welding more difficult disappears in friction stir welding because of not reaching to melting point of metal
during welding. In addition, mechanical properties of obtained weld joints were reach to base metal strength
level if suitable welding parameters are determined. Fractures usually occur either in heat affected zone or in
weld joint.
Investigations on the linear friction welding process through numerical simulations [3] was done by Livan
Fratini. LFW is a solid-state joining process applied to non-axis symmetric components and involves joining of
materials through the relative motion of two components undergoing an axial force. The force of friction
transformed into heat which cause local softening of material and the bonding occurs. In this paper process
conditions allowing effective bonding conditions were highlighted and local conditions of pressure and
temperature determining effective bonding of the specimens were determined. A dedicated prototype machine
has been designed and assembled in order to produce experimental test welds. Such conditions can be obtained
acting on the process parameters, namely the oscillation frequency of the specimens and the acted pressure. The
numerical model is able to effectively reproduce the process conditions. The subsequent stages and process
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