An Experimental Investigation of the Age Hardening of Copper with Manganese Silicide

The subject of the thesis was based upon the theory of precipitation or age hardening of the copper by the compound formed by the Manganese and silicon present in the ternary Cu-Mn-Si alloy. The effect of the heat treat­ment to such an alloy was to be studied and the best aging time and temperature was to be determined.

Porosity and Oil Absorption Properties of Metal Compacts of Copper - Tin - Graphite

Powder metallurgy, the most recent innovation in met­allurgical process, is not a new art; although not until recently did it become a matter of general interest, this being due not only to the products formed but also to the possibilities of future developments. The manufacture and application of metal powders is now beginning to take a position as a recognized part of the science of metallurgy.

An Investigation of the Age-Hardening of Copper with Nickel-Boron Compounds

Boron is an element whose metallurgical possibil­ities have never been fully investigated. The principal reason for this fact seems to lie in the difficulties encountered in preparing elemental boron and its various intermetallic compounds.

Age Hardening of Copper-Aluminum Alloy Castings

Age hardening occurs in alloys of the solid solution type containing a hardening constituent, be it metal or metallic compound, which is more soluble in the solvent phase at higher temperatures than at lower ones.

Bright Electroplating of Copper in the Acid Bath

Plating of various objects with mirror-like surfaces of chromium, nickel, and other metals has expanded considerably during the past decade, and now ranks as an important enterprise, particularly with respect to the automotive industry.

Hardness and Electrical Resistivity of Copper-Iron Powder Metal Compacts

Although powder metallurgical methods have been used for years to fabricate tungsten and platinum, very little scientific data have been recorded until the beginning of this century. A large percentage of all commercial production at present is based upon past practice rather than upon scientific knowledge.

Age Hardening of Copper Antimony Alloys

A large number of alloys of varying percentages of copper and antimony were prepared. These alloys were treated in various ways which might be expected to produce age hardening. The effect of cold working was studied in the range where the alloys were malleable.

The Electrodeposition of Copper-Cobalt Alloys

An attempt was made to deposit a 50:50 copper-cobalt alloy from various sulfate electrolytes. No true 50:50 alloy was obtained but various mixtures of cobalt and copper rich crystals were deposited.

The Anodic Polishing of Copper in Solutions of Orthophosphoric Acid

The electrolytic cleaning of metals by anodic methods has been known for many years. It was recognized long ago that when the temperature and concentration of the electro­lyte were properly regulated, bright clean surfaces were obtained.

The Effect of Manganese and Magnesium on the Hardening of Copper-Aluminum Alloys

During recent years, duralumin and all aluminum alloys have been made the object of much discussion regarding their hardening mechanism. The commercial success of nearly all of the alloys of aluminum and mag­nesium is dependent on their ability to age or precipitation harden.

An Investigation into the Precipitation of Copper from Mine Water, using Sulfur Dioxide to Reduce the Ferric Ion Content

The experiments which were preformed showed that sulfur dioxide would reduce the ferric ion content of the mine waters to a very low figure. The reduction in the ferric ion content would improve the efficiency of the precipitation process, and also increase the recovery of copper.

Operation Characteristics of the Series System for Electrolytic Refining of Copper

In the copper electrolytic refining operation, two main objectives are desired: the first is the production of a metal of desired chemical composition and physical characteristics, and the second is the recovery of the valuable by-products.

Elemental and Lead Isotopic Data of Copper Finds from the Singen Cemetery, Germany – a Methodological Approach to Investigate Early Bronze Age Trade Networks

We report a trace element - Pb isotope analytical (LIA) database on the "Singen Copper", a peculiar type of copper found in the North Alpine realm, from its type locality, the Early Bronze Age Singen Cemetery (Germany). What distinguishes “Singen Copper” from other coeval copper types? (i) is it a discrete metal lot with a uniform provenance (if so, can its provenance be constrained)? (ii) was it manufactured by a special, unique metallurgical process that can be discriminated from others? Trace element concentrations can give clues on the ore types that were mined, but they can be modified (more or less intentionally) by metallurgical operations. A more robust indicator are the ratios of chemically similar elements (e.g. Co/Ni, Bi/Sb, etc.), since they should remain nearly constant during metallurgical operations, and are expected to behave homogeneously in each mineral of a given mining area, but their partition amongst the different mineral species is known to cause strong inter-element fractionations. We tested the trace element ratio pattern predicted by geochemical arguments on the Brixlegg mining area. Brixlegg itself is not compatible with the Singen Copper objects, and we only report it because it is a rare instance of a mining area for which sufficient trace element analyses are available in the literature. We observe that As/Sb in fahlerz varies by a factor 1.8 above/below median; As/Sb in enargite varies by a factor of 2.5 with a 10 times higher median. Most of the 102 analyzed metal objects from Singen are Sb-Ni-rich, corresponding to “antimony-nickel copper” of the literature. Other trace element concentrations vary by > 100 times, ratios by factors > 50. Pb isotopic compositions are all significantly different from each other. They do not form a single linear array and require > 3 ore batches that certainly do not derive from one single mining area. Our data suggest a heterogeneous provenance of “Singen copper”. Archaeological information limits the scope to Central European sources. LIA requires a diverse supply network from many mining localities, including possibly Brittany. Trace element ratios show more heterogeneity than LIA; this can be explained either by deliberate selection of one particular ore mineral (from very many sources) or by processing of assorted ore minerals from a smaller number of sources, with the unintentional effect that the quality of the copper would not be constant, as the metallurgical properties of alloys would vary with trace element concentrations.

Reaction of Copper(II) Chloroacetate with Pyrazole. Synthesis of a One-Dimensional Coordination Polymer and Unexpected Dehydrochlorination Reaction

The reaction of copper(II) chloroacetate (1d) with pyrazole (Hpz) mainly yielded the mononuclear compound [Cu(μ-ClCH2COO)2(Hpz)2] (2m), which self-assembled generating a one-dimensional coordination polymer. Moreover, the concomitant isolation of the tetranuclear [{Cu2(μ-pz)(μ-OCH2COO)(Hpz)(MeOH)}2(μ-ClCH2COO)2] (3t) and hexanuclear [{Cu3(μ3-OH)(μ-pz)3(Hpz)2}2(μ-ClCH2COO)2](Cl)2 (4h) species evidenced the occurrence of a peculiar, previously unreported, dehydrochlorination reaction and the formation of the trinuclear triangular moiety [Cu3(μ3-OH)(μ-pz)3]. Theoretical calculations based on density functional theory including solvation effects indicate a possible pathway for the formation of 3t. Interestingly, besides the energy minimum corresponding to 3t, a further relative energy minimum is found for a species which can be considered a possible reaction intermediate.