Pressureless Consolidation of Metallic Powders

Details

• Personal Author:
  Holman JL Jr. ; McIlwain, J. F. ; Neumeier, L. A.
• Description:
  Pressureless consolidation of metallic powders is achieved by sintering, in a nonoxidizing atmosphere, a blend of the metallic powder with a small amount of finely divided lithium tetraborate. For example, a tool steel powder of 80-mesh particle size or finer, consisting of mo 4.9, W 6.3, Cr 4, V 2, mn 0.26, C 1 pct, the balance Fe, was blended with 0.5 Wt pct Li2B4O7, of about minus 100- mesh particle size by ball-milling for 1/2 h in a jar mill containing agate balls. Blended powder was loaded into an open ceramic-lined graphite mold, and the mold was vibrated to achieve a tap density of approximately 40 pct. The blended powder and mold then were heated to about 760 deg C for 1/2 h in either a helium atmosphere or in a vacuum of less than 5 x 10-2 torr, then the temperature was raised to about 1,225 deg C and held there for approximately 1 h per inch of starting powder thickness. The resulting product was found to have a sintered density of 94 pct of the theoretical density with the helium atmosphere and 92 pct with the vacuum. [Description provided by NIOSH]
• Subjects:
  Metals Occupational Health Safety
• Keywords:
  Metallic Compounds Metallurgical Processes
• Series:
  Mining Publications
• Document Type:
  Text
• Genre:
  Other
• Place as Subject:
  Missouri ; OSHA Region 7
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  RORC - Rolla Research Center
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  1-3
• NIOSHTIC Number:
  nn:10003210
• Citation:
  US Pat 4,407,775 1983 Oct; :1-3
• Federal Fiscal Year:
  1984
• Peer Reviewed:
  False
• Source Full Name:
  United States Patent 4,407,775
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:0a3a09cd3bac6aa966ed0af0fdccac5c1adddc5ef8ba926df5c2415aba1ecdcc854aec9998954e717fd4965cbbcba0f1e07b4d64b2de3def22e029460b30c4cc
• Download URL:
  https://stacks.cdc.gov/view/cdc/219456/cdc_219456_DS1.pdf
• File Type:
  [PDF - 232.31 KB ]