Method of forming chromium and aluminum diffusion alloys on metal pieces
Abstract
Abstract THE METAL PIECES TO BE TREATED ARE EMBEDDED IN A REACTIVE MASS CONTAINED IN A PARTLY GASTIGHT BOX PLACED IN A HEATING VESSEL WHEREIN THERE IS ANAT LEAST PARTLY HYDROGENATED PROTECTIVE ATMOSPHERE. THE REACTIVE MASS COMPRISES AN INTIMATE MIXTURE OF (1) A POWDER ALLOY OF CHROMIUM AND ALUMINUM, (2) AN INERT POWDERED DILUTING COMPONENT AND (3) A HALOGEN-CONTAINING COMPONENT. THE BOX AND ITS CONTENTS ARE HEATED TO 1050*C.-1100*C. FOR A FEW HOURS, THEN COOLED. THE STARTING CHROMIUM POWDER FOR THE CHROMIUM-ALUMINUM ALLOY POWDER MAY BE OF EITHER MAGNESOTHERMIC OR ELECTROLYTIC ORIGIN AND AT LEAST THE ELECTROLYTIC CHROMIUM IS SUBJECTED TO AT LEAST ONE PRETREATMENT, PRIOR TO ALLOYING, BY EXPOSURE TO EITHER MAGNESIUM OR CALCIUM VAPOR TO SUBSTANTIALLY REDUCE THE AMOUNT OF FREE OXYGEN ON AND IN THE CHROMIUM GRAINS.
Inventors
- 👤 Philippe Marie Galmiche
- 👤 Andre Hivert
Bibliographic Details
Claims Analysis
Total Claims: 0References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-09-12 | 1976-03-13 | 1976-09-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-12 | 1980-03-13 | 1980-09-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-12 | 1984-03-13 | 1984-09-12 | $7700.00 | Window Closed / Lapsed |