Titanium and Ti alloys

Production

POLEMA has produced titanium powder since 1961 by reducing titanium oxide with calcium hydride – a method developed at the PMI FGUP named after I.P. Bardin. The choice of calcium hydride as the reducer is explained by calcium's high activity, which allows it to reduce almost all metal and non-metal oxides regardless of their thermodynamic activity without forming hard solutions and chemical bonds with the reduced metal. The calcium remaining after the chemical-metallurgical treatment of the reduced product is contained in small quantities in the reduced metal, bound with oxygen.

Use

Titanium powders reduced with calcium hydride have an irregular form and extended particle surface, thanks to which it shapes very well in a steel die mould at relatively low pressures, as well as hydrostatic shaping in elastic membranes. The powders roll well into bands and are sintered in a vacuum or a neutral atmosphere.

The titanium powders RP-Ti grade S, RP-Ti grade M, RP-Ti grade OM are used in medicine; in the food industry, for making regenerating filters used in systems for purifying drinking and mineral waters, juices and other beverages; in production of highly dependable pyrotechnical substances and porous bulk getters (degasifiers) with high sorption capacity; and in production of parts for watch mechanisms and acid-resistant equipment. The powders are also used for plasma and microplasma coating deposition.

Brades and chemical composition

Grades	Ti	Admixtures, mass %,  maximum
		N	C	H	Fe+Ni	Si	Cl
RP-Ti grade K-1	base	0,07	0,05	0,35	0,35	0,10	0,003
RP-Ti grade K-2	base	0,20	0,05	0,35	0,35	1,00	0,003
RP-Ti grade S-1	base	0,08	0,05	0,35	0,40	0,10	0,004
RP-Ti grade S-2	base	0,20	0,05	0,35	0,40	1,00	0,004
RP-Ti grade M-1	base	0,08	0,05	0,35	0,40	0,10	0,004
RP-Ti grade M-2 RP-Ti grade M (A)-2	base	0,08	0,05	0,35	0,40	0,10	0,004
RP-Ti grade OM-1	base	0,08	0,05	0,40	0,40	0,10	0,004
RP-Ti grade OM-2	base	0,20	0,05	0,40	0,40	1,00	0,004

Sample chemical composition of RP-Ti grade M-1 powder

No	Ti	Admixtures, mass %
		C	O	N	S	Ca	Fe	Ni	Si	Al	Mg
1	base	0,046	0,25	0,08	0,002	0,22	0,050	0,17	0,040	0,01	<0,01
2	base	0,024	0,30	0,060	0,002	0,18	0,040	0,057	0,038	0,05	<0,01
3	base	0,045	0,28	0,050	0,003	0,30	0,030	0,040	0,032	<0,02	<0,02

Particle size, packed density and compressibility of powders

Grades	Granulometric composition, mass %, by fraction, micron				Packed density, g/cm3 *	Compressibility, g/cm3, at a pressure of MP *
	+280	+100	+45(40)	-45(40)		200	600
RP-Ti grade K	≤ 5,0	Balance (remainder)		≤ 10	0,89	2,70	3,50
RP-Ti grade S	≤ 1,0	n/a	≥ 25 (35)	Balance	1,15	2,60	3,24
RP-Ti grade M	0,0	≤ 2,0	≥ 15(25)	Balance	1,02	2,44	3,35
RP-Ti grade OM	0,0	≤ 1,0	≤ 5,0 (5,0)	Balance	1,36	2,72	3,48

* Average values (reference data)

Technical Specifications (TS) establish the packed density norm for RP-Ti grade K powder: 0.6-1.0 g/cm³ and the standardized granulometric composition for the powder RP-Ti grade M (A): +280 microns -  0.0%, +100 microns ≤ 1.0%, +45 microns – 15-40% (+40 microns – 25-50%), -45  (40) microns – remainder.

Sample powder particle shapes and distribution of particles by size

RP-Ti grade M. Distibution of particles by size

At the client's request, other requirements are possible for the chemical and granulometric compositions. In particular, for plasma coating deposition, a titanium product is produced with fractions of 40-100, 40-140, and 63-160 microns.