Hybrid Incremental Forming: Investigation on Localized …
153
1
st Stage – Preforming
2
nd Stage – SPIF
Fig. 1 Schematic representation of proposed HISF process
1. Development of HISF process for forming conical frustum of wall angle 50°.
2. Investigation on the effect of different parameters on sheet thinning and thickness
distribution in the formed part.
3. Investigation on the preform tool shape to improve thickness distribution along
the formed surface.
2 Materials and Methodology
2.1 Experimental Setup
All the experiments were performed on a 3 axis CNC milling machine (Batliboi
DART). A modular fixture is fabricated for holding the blank sheet on the work
table. Backing plate is provided to support to blank sheet and avoid further undesired
bending during the forming process. The blank sheet in the present HISF process is
aluminium Al 1050. Al 1050 is pure aluminium alloy which is well known for its
high ductility and excellent corrosion resistance. The blank sheet is cut in rectangular sections of 200 mm × 300 mm from a 1.24 mm thick sheet metal stock. The
Table 1 Mechanical properties of blank sheet
Material property
Unit
Value
Density
kg/m 3
2700
Young’s modulus
GPa
63.45
Ultimate tensile stress
MPa
146.144
% Elongation
–
5.8
Strain hardening exponent
–
0.301
Strength coefficient
MPa
133.64
153
1
st Stage – Preforming
2
nd Stage – SPIF
Fig. 1 Schematic representation of proposed HISF process
1. Development of HISF process for forming conical frustum of wall angle 50°.
2. Investigation on the effect of different parameters on sheet thinning and thickness
distribution in the formed part.
3. Investigation on the preform tool shape to improve thickness distribution along
the formed surface.
2 Materials and Methodology
2.1 Experimental Setup
All the experiments were performed on a 3 axis CNC milling machine (Batliboi
DART). A modular fixture is fabricated for holding the blank sheet on the work
table. Backing plate is provided to support to blank sheet and avoid further undesired
bending during the forming process. The blank sheet in the present HISF process is
aluminium Al 1050. Al 1050 is pure aluminium alloy which is well known for its
high ductility and excellent corrosion resistance. The blank sheet is cut in rectangular sections of 200 mm × 300 mm from a 1.24 mm thick sheet metal stock. The
Table 1 Mechanical properties of blank sheet
Material property
Unit
Value
Density
kg/m 3
2700
Young’s modulus
GPa
63.45
Ultimate tensile stress
MPa
146.144
% Elongation
–
5.8
Strain hardening exponent
–
0.301
Strength coefficient
MPa
133.64