Issue 47

K. Hachellaf et alii, Frattura ed Integrità Strutturale, 47 (2019) 459-467; DOI: 10.3221/IGF-ESIS.47.36 463 - Mix the materials to form the joint - Contain the flow of material under the shoulder and around the pin. The shoulder serves to bring heat by friction and to confine the kneaded material under the tool. Tool type: Pin profile : conical (T2) Process parameters Welding Quality Welded cord Rotation speed N (rpm) Advance speed a (mm/min) Test N° 1 875 24 Welding correct 2 875 40 Welding correct 3 1750 24 Bad Welding 4 1750 40 Bad Welding 5 720 24 No welding 6 720 40 Cracked cord Table 3b : Welding process parameters. R ESULTS AND DISCUSSIONS he experiment was successfully carried out on HDPE plates with a thickness of 4 mm with all the parameters selected. Examination of these welded samples by both types of tools gives some good results for welding quality. The samples relating to the welding by the two tools T1 and T2 for rotation speed of 875 rpm and advance speed of 24 and 40 mm/min have a satisfactory appearance. For other cutting parameters, we notice a bad quality of welding. We also noticed that with a cylindrical pin, the kneading zone of the welded sample had a good surface state, which proves the effectiveness of the tool for kneading the softened polymeric material (Tab. 3). When the linear welding operation is finished sample preparation is carried out for tensile tests (Fig. 6), tensile test specimens made of Dumbbell form according to ISO 3167. Tensile tests are carried out under room temperature. T