'Copper and Bronze in Art' and the Search for Rare Corrosion Products

Information taken from David A. Scott’s book “Copper and Bronze in Art” was crucial for research on copper corrosion products in Stuttgart. Examples discussed are the nature and variability of ‘Black Spots’ (aka ‘Brown Fuzzies’); cupric hydroxide by cleaning, patination, and pigment synthesis; the wondrous phenomenon of curly malachite; chalconatronite formed by contact to soda glass; the formation of copper formates by glass-induced metal corrosion; and synthesis and X-ray diffraction of basic copper acetates (‘verdigris’).

Effect of Tool Rake Angle and Crystal Orientation on Ductile Mode Cutting of Hard/Brittle Materials

The effects of negative rake angles on the ductile mode cutting of soda glass and sapphire were studied. In addition, the machining mechanism was studied using a groove-cutting model based on the orthogonal cutting theory. It was found that the specific cutting forces in ductile mode cutting increase on both the soda glass specimen and on the sapphire specimen when the rake angle of the tool becomes negative. The difference between the experimental data and theoretical data of the specific cutting forces becomes large when the tool has a high rake angle on the negative side. This is attributed to effects of the roundness of the edge, the effects of the roundness of the nose, and the plowing mechanism, which causes plastic flow of the work material to both sides of the groove. The specific cutting force of sapphire depends on the cutting direction against the crystal orientation. The specific cutting force of sapphire depends on the cutting direction in terms of the crystal orientation. The anisotropy of the cutting force of sapphire also depends on the rake angle of the tool.

Modelling and Optimization for Cutting Forces in Ultrasonic-Assisted Drilling of Soda Glass

Ultrasonic-Assisted Drilling (UAD) is a promising technology used for machining difficult-to-cut materials. In this work, an experimental investigation and statistical analysis are used to study the characteristics UAD and conventional drilling (CD) of soda glass using diamond abrasive tools. Statistically designed experiments were conducted using cutting fluid at different levels of tool feed rate, spindle speed, and tool abrasive-concentration. The mean thrust force and moment were considered the main responses. The significant drilling factors and their interactions were identified by modelling the process parameters and the output responses. The statistical models and optimum levels are determined. The ultrasonic application showed a significant effect on reducing the feed forces and drilling moment. Spindle speed is significant factor on thrust force and moment. The models error is less that 9%.

APPLYING NANODISPERSED MODIFIERS FOR PRODUCING SHIELDING POLYFUNCTIONAL COATINGS

The first mineral based lacquer and paint coating have been developed based on Portland cement and soda glass, which does not require traditional silicators of zinc oxide and is also capable of absorbing man-made radiation. A significant change in the structure of silicate paint has been achieved by its modification with multi-layered carbon nanotubes. The developed composition has water resistance, good adhesion to the base, the improved durability, is capable of operating at high temperatures; the life of coating is 3 times longer in comparison with its analogues.