Hardening of Dental Gold-Copper Alloys
X-ray diffraction studies of several proprietary dental gold alloys demonstrated that hardening probably is a dual mechanism of precipitation and order-hardening. Lattice parameter measurements showed that the ordered structure was AuCu. In addition, it was shown that maximum hardness occurs at about 75% full order.
Order-hardening in CuAu
Single crystals of CuAu were used to examine the changes in hardness, flow stress, and microstructure resulting from heat treatment at 150 to 340° C, which produces the tetragonal superlattice. The crystals, quenched from a high temperature, were in the disordered cubic form to begin with; some were also cold-rolled, to permit comparison of the ageing characteristics of as-quenched and of cold-worked specimens. The asquenched crystal hardened much more than the cold-rolled ones; a peak hardness was attained and followed by a fall in hardness. At 150° C, no microstructural changes were seen; at 240° C, spontaneous recrystallisation took place at grain boundaries; while at 340° C, there was twinning and spontaneous grain-boundary fracture. The observations are rationalised in terms of the various mechanisms for relief of the large microstrains that accompany ordering in this alloy.
Mechanism of Action of Antibacterial Agents
Similar ebooks with Mechanism Of Action Of Antibacterial Agents : bacterial structure and mechanisms of antimicrobial action antimicrobial agents1 a. definitions1 b. history1 c mechanism of action of antibacterial agents ahqgn mechanism of action of antibacterial agents ucovs mechanism of action of antibacterial agents oqdef mechanism of action of antibacterial agents grjos antifungal agents: mode of action, mechanisms of mechanism of action of antibacterial agents jrzfn mechanisms of antimicrobial resistance in bacteria toxicity of antibacterial agents: mechanism of action on antibacterial and antifungal drugs university home page the mechanism of the antimicrobial action of mechanism of action of nb2001 and nb2030, novel ty chemotherapeutic drugs i s r ve i un g o a xi metallic nanoparticles: mechanism of antibacterial action molecular mechanisms of bacterial resistance to antifungal agents objectives microblog mechanisms of antimicrobial resistance in bacteria ajic silver i: its antibacterial properties and mechanism of action chapter 5: antibacterial mechanism of action 5.