Titanium alloy powders

In titanium-alloy powder metallurgy, the blended-elemental approach implies the mixing of fine granular xmalloyed titanium with a powdered master alloy. According to Froes et al. [Fro85], the method has been applied to alloys Ti-6A1-4V (predominantly), Ti-6Al-6V-2Sn, Ti-... 

Compacted powder mixtures of titanium and titanium dihydride demonstrate the hydrogen-enhanced plasticity effects on deformation over 500 C, like titanium alloys hydrogenated from the gas phase. 

Significant advances have also been made by forging titanium alloy (T1-6A1-4V) and cobalt chromium alloys cold working multiphase cobalt based alloys and by hot isostatically pressing cobalt chromium alloy powders. The property values claimed by the manufacturers are far in excess of the minimum values specified in the British, American and International Standards... 

Chlorine has caused numerous accidents with metals. Beryllium becomes incandescent if it is heated in the presence of chlorine. Sodium, aluminium, aluminium/titanium alloy, magnesium (especially if water traces are present) combust in contact with chlorine, if they are in the form of powder. There was an explosion reported with molten aluminium and liquid chlorine. The same is true for boron (when it is heated to 400°C), active carbon and silicon. With white phosphorus there is a detonation even at -34°C (liquid chlorine). 

This process, originally designated as RSR (rapid solidification rate), was developed by Pratt and Whitney Aircraft Group and first operated in the late 1975 for the production of rapidly solidified nickel-base superalloy powders.[185][186] The major objective of the process is to achieve extremely high cooling rates in the atomized droplets via convective cooling in helium gas jets (dynamic helium quenching effects). Over the past decade, this technique has also been applied to the production of specialty aluminum alloy, steel, copper alloy, beryllium alloy, molybdenum, titanium alloy and sili-cide powders. The reactive metals (molybdenum and titanium) and... 

Powder Formation. Metallic powders can be formed by any number of techniques, including the reduction of corresponding oxides and salts, the thermal dissociation of metal compounds, electrolysis, atomization, gas-phase synthesis or decomposition, or mechanical attrition. The atomization method is the one most commonly used, because it can produce powders from alloys as well as from pure metals. In the atomization process, a molten metal is forced through an orifice and the stream is broken up with a jet of water or gas. The molten metal forms droplets to minimize the surface area, which solidify very rapidly. Currently, iron-nickel-molybdenum alloys, stainless steels, tool steels, nickel alloys, titanium alloys, and aluminum alloys, as well as many pure metals, are manufactured by atomization processes. 

The fuels are finely powdered metals (2.0-10.0 g) among which titanium, zirconium, manganese, tungsten, molybdenum and antimony are very common. Sometimes, non-metal powders such as boron and silicon (for fast burning delays), binary alloy powders such as ferrosilicon, zirconium-nickel, aluminum-palladium and metal compounds such as antimony sulfide, calcium silicide etc. are also used. 

Many kinds of artificial hip joints are available commercially, but they all consist of the same parts, i.e. a metal stem or shaft, usually made of a titanium alloy and a ceramic head of aluminium or zirconium oxide. The production of the ceramic head starts with a powder and ends with the sintering process. The heat treatment will cause the head to shrink. After production, the head is thoroughly tested, e.g. on its spherical shape and surface roughness. 

The kinetics of diamond powder infiltration with cobalt of VK15 sintered carbide and Co-Mo and Co-Ti melts was studied experimentally at 8 GPa (Fig, 1). Confidence intervals for T and k values, the reliability being a= 0,95, do not exceed 8 %. According to [3], the limit of WC solubility in Co attains 10 mass % or 3.2 at. %. The additive contents of Co-Mo and Co-Ti alloys was 10 mass % (accordingly, the atomic portions were 0.12 Ti and 0,064 % Mo). Samples of alloys were sintered from mixtures of cobalt-molibdenum and cobalt-titanium hydride powders in a vacuum furnace at 1000 °C. 

Ignition on contact with bromine pentafluoride (or violent reaction), chlorine trifluoride, fluorine, metals (powdered) + water, aluminum-titanium alloys + heat, metal acetylides (e.g., cesium acetylide, copper(I) acetylide, lithium acetylide, mbidium acetylide), nonmetals (e.g., boron ignites at 700°C), phosphoms, sodium phosphinate. Violent reaction with acetaldehyde, aluminum + diethyl ether, dipropylmercury, titanium (above 113°C). Incandescent reaction with cesium oxide... 

The methods described in detail in Section 36.2, or only mentioned, have been used as follows for spectrophotometric determination of palladium the thio-Michler s ketone — in silver, copper, and anodic slime [32], in catalysts [31] with thiosemicarbazide derivatives — in water [44] and alloys [46] with palladium-carbon powder — with a-benzilmonoxime [48] with PAR — in catalysts and ores [58] with thiazolylazo derivatives — in Ni-Al catalysts [63] with 5-Br-PADAP — in titanium alloys with pyridylazo derivatives - in nickel alloys [68] with sulphonitrophenol - in silver alloys [70] with Arsenazo III — in iron and meteorites and with Palladiazo — in catalysts, minerals, silica gel, and calcium carbonate [78]. 

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