2020 年 61 巻 2 号 p. 282-288
β-SiC coated SiC die material was employed to investigate the material compatibility between pure titanium in industrial grade I and covalent-bonded β-SiC coating. β-SiC coated SiC die with the coating thickness of 3 mm was first prepared as a staring die material. A micro-groove was machined onto the SiC coating by the picosecond laser machining. A titanium wire specimen with the diameter of 0.98 mm and the length of 20 mm, was upset into this micro-groove by fine CNC-stamping system. This SiC-coated SiC die was fixed into a cassette die. CNC up-setting procedure was employed for experiment to measure the torque power–stroke curve during upsetting at the specified reduction of thickness by 10%, 20% and 30%, respectively. In experiments, SEM, laser- and optical-microscopy were utilized to observe the titanium adhesive film formed onto the die surface. No metallic titanium was detected by SEM-EDX analysis at the contact area to upset titanium on this β-SiC coating even after continuously upsetting in fifteen shots. Titanium oxide debris flakes were splashed and printed as a very thin film onto the β-SiC die.
