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Liquid phase sintering is the process of adding an additive to the powder which will melt before the matrix phase. The process of liquid phase sintering has three stages: rearrangement – As the liquid melts capillary action will pull the liquid into pores and also cause grains to rearrange into a more favorable packing arrangement.
Operating a vacuum heat treating furnace, c. 1959–1962. A vacuum furnace is a type of furnace in which the product in the furnace is surrounded by a vacuum during processing. The absence of air or other gases prevents oxidation, heat loss from the product through convection, and removes a source of contamination.
The powder metallurgy "press and sinter" process generally consists of three basic steps: powder blending (or pulverisation), die compaction, and sintering. Compaction of the powder in the die is generally performed at room temperature. Sintering is the process of binding a material together with heat without liquefying it.
The process takes place under vacuum, which makes it suited to manufacture parts in reactive materials with a high affinity for oxygen, e.g. titanium. [3] The process is known to operate at higher temperatures (up to 1000 °C), which can lead to differences in phase formation though solidification and solid-state phase transformation .
The process was invented in Hanau, Germany in 1917. Heraeus Vacuumschmelze and Dr. Wilhelm Rohn applied for a patent on vacuum melting on 12 January 1918 and were granted a German patent DE 345161. [3] Edwin Fitch Northrup built the first prototype of a vacuum induction furnace in the United States of America in 1920. [citation needed]
Vacuum impregnation is a preferred OEM process that seals porosity and leak paths in metal castings, sintered metal parts and electrical castings that form during the casting or molding process. Vacuum impregnation stops casting porosity (a phenomenon that occurs in the die-cast manufacturing process and allows manufacturers to use parts that ...
Direct metal laser sintering [4] Filament winding, produces composite pipes, tanks, etc. [3] Fused deposition modeling [3] Inkjet Printing [5] Laminated object manufacturing [3] Laser engineered net shaping [3] Layered manufacturing [3] Rapid Induction Printing; Selective laser sintering [3] Spark plasma sintering; Stereolithography [3]
Vacuum metallurgy is the field of materials technology that deals with making, shaping, or treating metals in a controlled atmosphere, at pressures significantly less than normal atmospheric pressure. [1] The purpose of vacuum metallurgy is to prevent contamination of metal by gases in the atmosphere.