John Trowbridge

The magnetism of nickel and tungsten alloys

THE fact that different kinds of steel, alloyed in small proportions with Tungsten or Wolfram, and magnetized to saturation, increase in spe cific magnetism,* has long been known. Whether the same effect would result from the use of Nickel alloyed with Tungsten has never been investigated. This paper has for its object a partial answer to the query. It was instigated by Mr. Wharton, proprietor of the American Nickel Works, whose chemist, Mr. Riddle, kindly prepared the alloys which have been employed. These alloys were in two groups. The first, received in November, 1888, consisted of three bars of the same shape, one being of pure nickel and the other two having respectively 3 and 4 per cent of tungsten in alloy. These bars were rolled from cast ingots, which were toughened by the addition of magnesium after Fleitmanns method, the magnesium being added just before pouring. They were hot when rolled. The one of pure nickel was afterwards planed into regular shape. Those containing tungsten were too brittle to allow of this manipulation. They were, however, of sufficient regularity to permit accurate measurements. This group contained also an octagonially shaped bar with 8 per cent of tungsten, which was prepared like the others, and was afterwards ground into shape. The second group, received in May, 1889, contained bars which were simple castings, made without the addition of magnesium, and consisted of pure nickel and alloys with 1, 2, 3, and 6 per cent of tungsten. All the bars in this group were extremely hard and brittle. In making them, tungsten oxide, of weight calculated to yield the de sired percentage of tungsten in the resulting alloy, was placed with