Hybrid HIPIMS and DC magnetron sputtering deposition of TiN coatings: Deposition rate, structure and tribological properties

High power impulse magnetron sputtering (HIPIMS) has the advantage of ultra-dense plasma deposition environment although the resultant deposition rate is significantly low. By using a closed field unbalanced magnetron sputtering system, a hybrid process consisting of one HIPIMS powered magnetron and three DC magnetrons has been introduced in the reactive sputtering deposition of a TiN hard coating on a hardened steel substrate, to investigate the effect of HIPIMS incorporation on the deposition rate and on the microstructure and mechanical and tribological properties of the deposited coating. Various characterizations and tests have been applied in the study, including XRD, FEG-SEM, cross-sectional TEM, Knoop hardness, adhesion tests and unlubricated ball-on-disk tribo-tests. The results revealed that, both the DC magnetron and hybrid-sputtered TiN coatings exhibited dense columnar morphology, a single NaCl-type cubic crystalline phase with strong (220) texture, and good adhesion property. The two coatings showed similar dry sliding friction coefficient of 0.8 – 0.9 and comparable wear coefficient in the range of 1 – 2× 10-15 m3N-1m-1. The overall deposition rate of the hybrid sputtering, being 0.047 μm/min as measured in this study, was governed predominantly by the three DC magnetrons whereas the HIPIMS only made a marginal contribution. However, the incorporated HIPIMS has been found to lead to remarkable reduction of the compressive residual stress from -6.0 to -3.5 GPa and a slight increase in the coating hardness from 34.8 to 38.0 GPa

Lúpus eritematoso sistêmico bolhoso: diagnóstico diferencial com dermatite herpetiforme

O lúpus eritematoso sistêmico bolhoso é um subtipo raro do lúpus eritematoso sistêmico, que ocorre ainda de forma mais incomum nos pacientes pediátricos. Relatamos o caso de uma adolescente de 12 anos, apresentando lesões vésico-bolhosas em face, pescoço, tronco, mucosas oral e genital, anemia, leucocitúria estéril, FAN: 1/1280 padrão nuclear pontilhado grosso, Anti-Sm e Anti-RNP positivos. O estudo anatomopatológico sugere dermatite herpetiforme e a imunofluorescência direta revela IgG, IgA e fibrina ao longo da zona de membrana basal. Apresentamos um caso típico de lúpus eritematoso sistêmico bolhoso e enfatizamos a importância do diagnóstico diferencial com a dermatite herpetiforme<br>Bullous systemic lupus erythematosus is a rare subset of systemic lupus erythematosus that is even rarer in pediatric patients. We report a case of a 12-year-old girl who presented with a vesiculobullous eruption on her face, neck, trunk and genital and oral mucosa, as well as anemia, sterile pyuria, ANA (1:1280, speckled pattern) and positive anti-Sm and anti-RNP. Pathological examination suggested dermatitis herpetiformis, and direct immunofluorescence revealed IgG, IgA and fibrin in the epithelial basement membrane zone. We present a typical case of bullous systemic lupus erythematosus and emphasize the importance of clinical and histopathological differential diagnosis with dermatitis herpetiformi