High-temperature Corrosion of AlCrTiSiN Film in Ar-1%SO 2 Gas
AlCrSiN film with a composition of 29.1Al-17.1Cr-2.1Si-51.7N in at. % was deposited on a steel substrate by cathodic arc ion plating at a thickness of 1.8 μm. It consisted of nanocrystalline hcp-AlN and fcc-CrN, where a small amount of Si was dissolved. Corrosion tests were carried out at 800 ◦C for 5–200 h in Ar-1%SO2 gas. The major corrosion reaction was oxidation owing to the high oxygen affinity of Al and Cr in the film. The formed oxide scale consisted primarily of (Al,Cr)2O3, within which Fe, Si, and S were dissolved. Even after corrosion for 200 h, the thickness of the scale was about 0.7–1.2 μm, indicating that the film had good corrosion resistance in the SO2-containing atmosphere.
Influence of Al and Si content on structure and mechanical properties of arc evaporated Al-Cr-Si-N thin films
Abstract The effect of Al and Si on development of structure and mechanical properties was studied for arc evaporated Al–Cr–(Si)–N films synthesized from Al–Cr and Al–Cr–Si composite targets. All films show stoichiometric compositions, with a Si content corresponding to the target and a minor loss of Al. The hardness of Al–Cr–N films reaches a maximum for Al/Cr ratios close to the solubility limit of AlN in CrN. The addition of Si results in a further increase of hardness due to solid solution hardening and formation of a nanocomposite structure, which is accompanied by a reduced crystallinity and grain size. Al–Cr–Si–N films with high Si contents show a reduced hardness due to grain boundary sliding promoted by the higher amorphous phase fraction.
The Poet, The Critic, and the Moralist: Horace, Epistles 1.19
I begin by quoting from two valuable recent works on Horace. Professor Brink in his Horace on Poetry (1964) writes: ‘The centre of the short piece lies in lines 21—34. Readers, among them critics and poets, had denied one aspect of the Odes which was surely above criticism—the striking originality of these poems. Horace's defence turns on the question of originality’ (p. 180) and ‘Epistle 19 is unique in that it alone among the literary satires and letters reiterates Horace's claim to be the Latin fidicen’ (p. 182). And Dr. McGann in his Studies in Horace's First Book of Epistles (Collection Latomus 100: 1969): ‘In Ep. 19... as in the literary satires, Horace is a practising poet or at least a very recently practising one, engaged in defending himself against hostile criticism’ (p. 40) and ‘As the only epistle concerned exclusively with literary matters, the nineteenth stands apart’ (p. 82).