The effect of TiO₂ particles on microstructural evolutions of HSLA steels subjected to friction stir welding

Enhancing the tribological properties of pure Ti by pinless friction surface stirring

“…In agreement with the previous studies [29,30], the second possible mechanism responsible for the hardening of FSSed CP-Ti is the dispersion hardening of ultra-hard TiN particles (2400-2800 HV [31]) as well as hard TiO 2 particles (∼ 1400 HV) [32]. Indeed, due to the significant increase in the temperature of the SZ of FSSed sample (Figure 5(a)) TiN particles (Figure 4(a)) with the EDS analysis shown in Figure 4(b) are thought to be formed in situ as a result of inward diffusion and subsequent reaction of surrounding atmosphere nitrogen atoms with the SZ Ti atoms.…”

“…In agreement with the previous studies [29,30], the second possible mechanism responsible for the hardening of FSSed CP-Ti is the dispersion hardening of ultra-hard TiN particles (2400-2800 HV [31]) as well as hard TiO 2 particles ( ∼ 1400 HV) [32]. Indeed, due to the significant increase in the temperature of the SZ of FSSed sample (Figure 5 It is generally accepted that severe plastic deformation can markedly increase the dislocation density of the processed zone.…”