24/06/2005 - Controller General of Patents, Designs, and Trade Marks

(21) Application No. 332/DEL/1999 A (22) Date of filing of Application: 25/02/1999
(54) Title of the invention: “A PROCESS FOR PREPARATION OF SINTERING ADDITIVES IN
POWDER FORM USEFUL FOR SINTERING OF SILICON CARBIDE.”
(51) International Classification 7 :
C04B 35/583; C08K 3/34
(30) Priority Data :
(31) Document No.:NIL
(32) Date : NIL
(33) Name of convention country : NIL
(66) Filed U/s 5(2) : NIL
(61) Patent of addition to application No. :
NA
(62) Filed on : NA
(63) Divisional to Application No. :NIL
(64) Filed on : NA
Total No of Pages: 15
(71) Name of the applicant:
COUNCIL OF SCIENTIFIC INDUSTRIAL &
RESEARCH
Address of the Applicant:
Rafi Marg New Delhi–110001
(72) Name of the Inventor:
SANKAR GHATAK
AMIYASANKAR SANYAL
KAJAL KUMAR DHARGUPTA
SANTANU MANDAL
(57) Abstract:
The invention relates to a process for preparation of sintering additives in powder form
useful for sintering of silicon carbide. The process steps comprises; mixing aluminum oxide and
aluminum nitride in attritor mill using alumina balls in the molar proportion of 5 to 95, separating
the milled powder from alumina balls by sieving through 100 mesh B. S., preparing a slurry by
known methods using organic solvents as herein described, drying the said slurry to obtain a
powder, firing the said powder containing aluminum oxide and aluminium nitride at a temperature
in the range of 1750–1850 0 C under nitrogen atmosphere for a period in the range of 1–5 hours,
grinding the product by known methods in presence of organic solvents as defined above, drying
the said slurry to obtain sintering additives in powder form.
18170