Process for making highly reactive sub-micron amorphous titanium diboride powder

• US 4,888,166 A
• Filed: 09/03/1986
• Issued: 12/19/1989
• Est. Priority Date: 09/03/1986
• Status: Expired due to Term

• Current Assignee: Georgia Tech Research Corporation (University System of Georgia)
• Original Assignee: Georgia Tech Research Corporation (University System of Georgia)
• Inventors: Logan, Kathryn V.
• Primary Examiner(s): Doll, John
• Assistant Examiner(s): RUSSEL, JEFFREY E
• Application Number:
  US06/903,265
• Time in Patent Office: 1,203 Days
• Field of Search: 423/297, 75/27
• US Class Current: 423/297
• CPC Class Codes: C01B 35/04 Metal borides
• CPC Class Codes: C04B 35/58071 based on titanium borides
• CPC Class Codes: C04B 35/645 Pressure sintering

Abstract

A method of producing submicron titanium diboride from an initial mixture of titanium oxide, boron oxide, and magnesium, by reducing the titanium dioxide and boron oxide with magnesium in an atmosphere including air to yield a resultant product containing submicron titanium diboride and magnesia. The reduction reaction is preferably initiated by locally igniting the initial mixture. The resultant product is then cooled and leached with a leaching solution having a pH in the range of about 0.5 to about 8 to recover the sub-micron titanium diboride.

Claims

1. The method of making sub-micron titanium diboride which comprises the steps of forming a powdered reaction mixture consisting essentially of titanium oxide, boron oxide and magnesium, exothermically reacting the reaction mix in an atmosphere including air to yield a reacted mass containing titanium diboride and magnesia, and leaching the reacted mass with a leaching solution having a pH in the range of about 0.5 to about 8, to recover the sub-micron titanium diboride.

2. The method of claim 1, wherein the exothermic reaction is initiated by local ignition.

3. The method of claim 1, wherein the magnesium and B₂ O₃ are present in weight amounts within the range of about 5-30% in excess of their stoichiometric amounts.

4. The method of making titanium dioboride of sub-micron size in situ which comprises the steps of reducing titanium oxide and boron oxide with magnesium in an atmosphere including air to yield a reacted mass containing sub-micron titanium diboride and magnesia, leaching the reacted mass with a leaching solution having a pH in the range of about 0.5 to about 8, and recovering sub-micron titanium diboride.

5. The method of claim 4, wherein the reduction of titanium oxide and boron oxide with magnesium is initiated by local ignition.

6. The method of claim 4, wherein the magnesium and B₂ O₃ are present in weight amounts within the range of about 5-30% in excess of their stoichiometric amounts.

7. The method of claim 4, wherein the step of reducing titanium oxide and boron oxide with magnesium includes feeding the reactants through a funnel into a hot zone within the funnel and igniting the reactants within the hot zone.

8. The method of claim 7, wherein the reactants are ignited by local ignition.

9. The method of making amorphous titanium diboride of sub-micron particle size, which comprises the steps of:

forming a powdered reaction mixture consisting essentially of titanium oxide, boron oxide and magnesium in which the magnesium and B₂ O₃ are present in weight amount within the range of about 5-30% in excess of their stoichiometric amounts;

locally igniting said reaction mixture in an atmosphere including air to react the reaction mixture exothermically;

cooling the resultant product from the exothermic reaction;

leaching the reacted mass with a leaching solution having a pH in the range of about 0.5 to about 8, until the reacted, leached mass contains substantially only titanium diboride int he leaching solution; and

then

recovering amorphous, sub-micron titanium diboride powder from the leaching solution.

10. The method of claim 9, wherein the magnesium and boron oxide are present in weight amounts of about 10% in excess of their stoichiometric amounts.

11. The method of making titanium diboride which comprises the steps forming a powdered reaction mixture consisting essentially of titanium oxide, boron oxide and magnesium, exothermically reacting the reaction mixture in an atmosphere including air to yield a reacted product containing titanium diboride and magnesia, rapidly cooling the reacted product and then leaching the reacted product with a leaching solution having a pH in the range of about 0.5 to about 8, to recover sub-micron titanium diboride.

12. The method of claim 11, wherein the step of exothermically reacting the powdered reaction mixture includes feeding the reaction mixture through a funnel into a hot zone within the funnel and igniting the reactants within the hot zone.

13. The method of claim 12, wherein the reactants are ignited by local ignition.