1 Introduction
2 Methodology
2.1 Experimental Setup
2.2 Forming Device
Element | H | C | N | O | Fe | Ti |
---|---|---|---|---|---|---|
Mass fraction (%) | 0.01 | 0.08 | 0.08 | 0.10 | 0.12 | Balance |
Density (kg/m3) | Elastic modulus (GPa) | Dynamic yield strength (GPa) | Poisson ratio ν |
---|---|---|---|
4430 | 107.9 | 1.345 | 0.342 |
2.3 Surface Observation and Quality Characterization
2.3.1 Surface Topography Measurement
2.3.2 Measurement of Thickness Thinning Ratio
3 Results and Discussion
3.1 Surface Topography of Bulging Parts
3.2 Forming Depth of Bulging Parts under Different Incident Pressures and Their Profiles
Incident pressures (MPa) | 8 | 12 | 16 | 20 | |
---|---|---|---|---|---|
Forming depth (µm) | 1 | 79.5 | 129.7 | 144.6 | 230.4 |
2 | 94.1 | 158.5 | 165.7 | 192.3 | |
3 | 57.9 | 137.0 | 154.6 | 208.5 | |
4 | 89.1 | 132.7 | 190.3 | 234.0 | |
5 | 78.5 | 161.2 | 163.9 | 214.5 | |
6 | 93.2 | 140.4 | 146.7 | 248.9 | |
7 | 81.9 | 121.2 | 187.2 | 194.7 | |
8 | 66.8 | 115.7 | 148.8 | 218.1 | |
Average | 80.1 | 137.1 | 162.7 | 217.7 |
3.3 Surface Morphology of Bulging Parts
Type | Incident pressure (MPa) | Forming depth (µm) | Ra (µm) | |||
---|---|---|---|---|---|---|
Line a | Line b | Line c | Average | |||
Original sample | ~ | ~ | 0.292 | 0.284 | 0.287 | 0.288 |
Mold | ~ | ~ | 1.042 | 0.814 | 0.947 | 0.934 |
Bulging parts | 8 | 79.5 | 0.764 | 0.565 | 0.616 | 0.648 |
12 | 137.0 | 0.826 | 1.049 | 0.900 | 0.925 | |
16 | 163.9 | 1.219 | 1.358 | 1.201 | 1.259 | |
20 | 218.1 | 1.917 | 1.922 | 1.579 | 1.806 |