If there be a moderate amount of silver in the copper, he alloys it fourfold; for instance, if in three-quarters of a centumpondium of copper there is less than the following proportions, i.
The foreman of the works, according to the different proportions of silver in each centumpondium of copper, alloys it with lead, without which he could not separate the silver from the copper.
Thus the silver, as in the last process, is converted into a sulphide, and is absorbed in the regulus, while the metallic antimony alloyswith the gold and settles to the bottom of the pot.
This is carried on in a building near by the works, or in the works in which the gold or silver ores or alloys are smelted.
The general knowledge of the constituents of alloys which is implied, raises the question as to whether the Greeks did not know a great deal more about parting metals, than has been attributed to them.
The smelter, when he alloys copper with lead, with his hand throws into the heated furnace, first the large fragments of copper, then a basketful of charcoal, then the smaller fragments of copper.
They make twelve weights, which they use whenever they wish to assay alloys of silver and copper.
They often form liquid solutions, similar to alloys in metals.
Like Au it has little affinity for other elements, but alloys with many metals.
Gold is rarely found combined, and has small affinity for other elements, though forming alloys with Cu, Ag, and Hg.
Gun-metal, bell-metal, and speculum-metal are eachalloys of Cu and Sn.
Only alloys of Al have yet been obtained by this process.
Unfortunately the most refractory metals, such as platinum and alloys of platinum with iridium, fuse at a temperature of about 3450 degrees Fahrenheit.
They were to be over an inch thick, an unnecessary thickness, perhaps, but they had no need to economize weight, as witnessed by their choice of steel instead of light metalalloys throughout the construction.
National standards of mass have been made of alloys of iridium and platinum.
The alloys of iron and steel have now attained importance and a new science known as metallography has developed.
These three alloys are, therefore, the best for the manufacture of compasses, those of copper and nickel being the most malleable.
The various alloys then in existence showed little advantage over the pure metal, so pure aluminium was specified and ordered.
Alloys with iron can be prepared by reducing the mixed oxides with carbon in an electric furnace; these alloys are used to some extent in preparing special kinds of steel.
Many useful alloys contain tin, some of which have been mentioned in connection with copper.
They occur closely associated in nature, usually as alloys of platinum in the form of irregular metallic grains in sand and gravel.
The gold sticks to the mercury or alloys with it, and after a time the gold and mercury are scraped off and the mixture is distilled.
It imparts to its alloys high density, rather low melting point, and the property of expanding on solidification.
The chlorine is evolved as a gas at the anode, while the sodium alloys with the melted lead which forms the cathode.
Then alloys had to be sought which would have a temperature effect of small amount, and which were stable and durable in all their properties.
The comparison of the different metals and alloys available was a most important but exceedingly laborious series of investigations, carried out mainly by Dr.
He was accustomed in after years to present to his friends razors formed from one of the alloys then discovered.
In the case of alloys and impure metals, cold brings about a much smaller decrease in resistivity, and the continuations of the curves at no time show any sign of passing through the zero point.
Chart of the Variation of Electrical Resistance of Pure Metals and Alloys with Temperature.
Electrical Resistance of Metals and Alloys at Temperatures approaching the Absolute Zero," ibid.
Thermoelectric Powers of Metals and Alloysbetween the Temperatures of the Boiling-point of Water and the Boiling-point of Liquid Air," ibid.
Electrical Resistance of Pure Metals, Alloys and Non-Metals at the Boiling-point of Oxygen," Phil.
The production of refined steel, special alloy steels, and certain non-ferrous alloys is also carried out in electric furnaces of various types.
With certain alloys the change is so slight as to be negligible.
The success of the recent applications of electricity in the production of certain metals and alloys led Dr.
So locally intense indeed was the heat within a certain zone, that all the oxygen contained in the mixture was expelled and alloys of iron, aluminum, and calcium combined with more or less silicon, and phosphorus were produced.
Various alloys of metal are fusible at temperatures sufficiently low for this purpose.
This product was known fully seven hundred years before the Christian era, and was used in the making of guns until superseded by the various steel alloys of our day.
Are the alloys of all metals harder than the metals of which they are made?
In addition, they may be added to metallic fusions, for deoxidizing and also to communicate to the commercial alloys (such as bronze, brass, etc.
The works of Terre Noire especially made at the same time, in the blast furnace, ferro-silicon with manganese, alloys which are daily becoming more important for the manufacture of steels tempered soft and half soft without blowing.
The firstalloys of manganese and copper were made in 1848, by Von Gersdorff; soon after Prof.
Manhès used these same alloys for the fusion of bronze and brass, and recommended the following proportions: 3 to 4 kilog.
This results in a white, ductile metal, which is easily worked and susceptible of receiving a beautiful polish, like the alloys of nickel, which it may in time completely replace.
Such results show beyond contradiction the great interest there is in economically producing alloys of copper, manganese, tin, zinc, etc.
The following are some of the results obtained from thirteen alloys obtained in this manner.
While many investigators have tried to form alloys of copper and manganese by combining them in the metallic state (that is to say, by the simultaneous reduction of their oxides), the Hensler Bros.
The following tables of binary alloys exhibit this circumstance in experimental detail:-- Alloys having a density Alloys having a density greater than the mean of less than the mean of their constituents.
Thus poorer and poorer lead is got on the one hand, and richer and richer alloys on the other.
The mercurial alloysor amalgams are, perhaps, exceptions to this rule.
But, as alloys are generally soluble, so to speak, in each other, this definiteness of combination is masked and disappears in most cases.
Many alloysconsist of definite or equivalent proportions of the simple component metals, though some alloys seem to form in any proportion, like combinations of salt or sugar with water.
The most direct evidence of a chemical change having been effected in alloys is, when the compound melts at a lower temperature than the mean of its ingredients.
Having described the different alloys of copper and tin, I shall now treat of the method of separating these metals from each other as they exist in old cannons, damaged bells, &c.
Chaudet has made some experiments on the means of detecting the metals of alloys by the cupelling furnace, and they promise useful applications.
The statue of Desaix in the Place Dauphine, and the column in the Place Vendome are noted specimens of most defective workmanship from mismanagement of the alloys of which they are composed.
We have said that the difference of fusibility was often an obstacle to metallic combination; but this circumstance may also be turned to advantage in decomposing certain alloys by the process called eliquation.
Each of these alloys (a) and (b) will be joined to alloys of like quality obtained in the treatment of one or several other portions of three tons of the primitive alloy.
One of the alloys most useful to the arts is brass; it is more ductile and less easily oxidised than even its copper constituent, notwithstanding the opposite nature of the zinc.
Gold, silver, and platinum, and alloysof these metals 24.
Nickel, aluminium, and alloys having for a basis these metals: 69.
Copper and alloysof common metals with copper (brass, bronze, etc.
Steinmetz's formula applies only for very weak inductions when the alloys are at the ordinary temperature, but at the temperature of liquid air it becomes applicable through a wide range of inductions.
A number of iron alloys have been examined by Mme.
In all such magnetizable alloys the presence of manganese appears to be essential, and there can be little doubt that the magnetic quality of the mixtures is derived solely from this component.
If this view is correct, it may also be possible to prepare magnetic alloys of chromium, the only other paramagnetic metals of the iron group.
Certain non-magnetizable alloys of nickel, chromium-nickel and chromium-manganese were rendered magnetizable by annealing.
The magnetic qualities of various alloys of iron have been submitted to a very complete examination by W.
Practically the metals iron, nickel and cobalt, and some of their alloys and compounds constitute a class by themselves and are called ferromagnetic substances.
In the case of the ferromagnetic metals and some of their alloys and compounds, the permeability has generally a much higher value.
The following table gives the exact composition of some alloys which were found to be non-magnetizable, or nearly so, in a field of 320.
They found that the hysteresis-loss, which at ordinary temperatures is very small, was increased in liquid air, the increase for the alloys containing less than 30% of nickel being enormous.
Alloys containing different proportions of nickel were found to exhibit the phenomenon, but the two critical temperatures were less widely separated.
Magnetic Properties of Alloysand Compounds of Iron.
Higher strengths than this can be obtained by the use of special alloys for the filling material or by rolling.
Special attention has been given to definite directions for handling the different metals and alloys which must be handled.
Spelter is variously composed of alloys containing copper, zinc, tin and antimony, the mixture employed depending on the work to be done.
The composition of various alloys will give an idea of the difficulties to be contended with by consulting the information on welding various metals.
Copper is also used in alloys with other metals, forming an important part of brass, bronze, german silver, bell metal and gun metal.
The commonest alloy containing nickel is german silver, although one of its most important alloys is found in nickel steel.
Tin forms an important part of many alloys such as babbitt, Britannia metal, bronze, gun metal and bearing metals.
Nickel steel rods may be used for parts requiring great strength, but vanadium alloys are very difficult to handle.
The emission of white smoke indicates that the zinc contained in these alloys is being burned away and the heat should immediately be turned away or reduced.
The alloys of metals are, almost without exception, more important from an industrial standpoint than the metals themselves.
The metals and their alloys are described under this heading in the first chapter of this book and a tabulated list of the most important points relating to each metal will be found at the end of the present chapter.
All alloys of metals having mercury are called amalgams.
Various alloys are thus made which require a high temperature to flux properly, and these are the ones to use in joining steel to steel, the parts to be united requiring an intense furnace heat.
A soft solder is usually employed where lead, tin, or alloys of lead, tin and bismuth are to be soldered.
Copper and its alloys are subject to the same far-reaching changes as iron, but the action is less rapid.
The metals or metalloids of thealloys can unite independently with oxygen, sulphur, or carbonic acid, etc.
Mitzopulos[43] described the green patina of the copper alloysfound in Mycene as malachite and atacamite upon a reddish layer of cuprous oxide.
Carbon is usually designated by "points" and the other alloys by percentages.
In the simpler carburized steels it is not necessary to test the forgings for hardness after annealing, but with the high percentages of alloys in the carburizing steels and the heat-treated steels a hardness test is essential.
One of the things which sometimes confuse regarding the contents of steel is the fact that the percentage of carbon and the other alloys are usually designated in different ways.
For it is not alone the quality of the steel itself or the alloys used in its composition, but the proper working or treatment of the steel which determines whether or not the best possible use has been made of it.
This ratio, however, does not give the whole story of nickel-chromium combinations, and many surprising results have been obtained with these alloys when other percentage combinations have been employed.
In addition to the large amount of heat liberated when a metal solidifies, there are other changes indicated by the thermal analysis of many alloys which occur after the body has become entirely solidified.
This is true of all alloys which contain complex carbides, i.
High speed steel is one of the most complex alloys known.
Commercial steels of even the simplest types are therefore primarily alloys of iron and carbon.
It is possible that when the effect of tungsten with iron-carbon alloys is better known, a greater improvement can be expected from these steels.
It will be safe to say that each of these two systems of alloys have their own particular fields and chrome-vanadium steel should not be regarded as the sole solution for all problems, neither should nickel-chromium.
The automotive field has done much to develop not only new alloys but efficient methods of working them and has been drawn on liberally so as to show the best practice.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "alloys" in a variety of sentences. We hope that you will now be able to make sentences using this word.
