Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22C—FOUNDRY MOULDING
  • B22C9/00—Moulds or cores; Moulding processes
  • B22C9/10—Cores; Manufacture or installation of cores
  • B22C9/105—Salt cores

Definitions

• the thus produced sintered cores are available for use therein 15 in preparing hollow castings by suitably placing them in It is known to produce cast articles having voids therein the casting die and casting an appropriate material about by forming soluble cores and casting the desired article hem- It may in some cases be desirable to smooth out about the core or cores. After the article has been cast, the surfaces and particularly the edges of the sintered core. the cores are dissolved out thereby leaving the desirable This may be accomplished by sanding or grinding as the voids in the casting.
• One particularly desirable applica- 04186 y tion of this practice is in the manufacture of cylinder It has been found to be desirable in making use of the blocks for internal combustion engines.
• Channels for thus prepared sintered cores, to preheat them prior to cooling Water are suitably cast into the block by the insertion in the casting mold.
• it may be referred to technique of fugitive cores. practical to transfer the cores hot from the sintering step It has been the practice in the past to utilize water soluescribed directly to the casting mold. It has been found ble ma erials as the fugitive cores since they can be advisable to provide the sintered core at a temperature of dissolved and washed out most easily and economically.
• b ut 5-0 to 300 C Where such core is to be used in Exemplary of the water soluble core materials which the production of hollow metal castings.
• metal halide salts particularly sodium ings are to be made of materials having a lower melting and potassium chloride. These materials are quite inex- 3 Point, it y be desirable to Provide the sintered Cores at pensive as Well as easy to Work with and readily somewhat lower temperatures. recoverable.
• One specific example of a core made according to this It has been found that simple moldings and castings invention contained 95 weight percent: sodium chloride, produced in the prior art manner are excellent. However, 3 Weight percent borax, 1 weight percent magnesium oxide it has been found that in producing intricately shaped and 1 weight percent talc.
• Cores for use in this invention are suitably prepared by molding an appropriate mixture of metal halide and the References Cited second constituent into the shape of the void desired in UNITED STATES PATENTS the final casting.
• the shaped core is then dried and heated 1 523 5 9 25 Gibbons 0 3 9 to a sintering temperature by which treatment the core 554 97 9 1925 Alden 254-317 shape becomes dimensionally stable and strong enough 1,603,262 10/1926 Ald 106 .38,9 to withstand greater thermal and mechanical stresses than 2,420,851 5/ 1947 Zahn et a1. 164---35 was possible with prior art cores.
• the sintered salt cores according to the invention have 3,131,999 5/1964 Suzuki et a1.
• 164-16 also further advantageous properties. Owing to their 3,218,684 11/1965 Spink 164--79 porous sinter structure they are able e.g. to eliminate the V detrimental effect of the gas formation inevitably occur- SPENCER OVERHQLSEK p'lmary Emwnerring during the solidification of technical aluminum melts E, MAR, Assistant Examiner.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Molds, Cores, And Manufacturing Methods Thereof (AREA)
• Mold Materials And Core Materials (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=7434181

Family Applications (1)

Country Status (3)

Cited By (18)

Families Citing this family (8)

Citations (7)

• 1965
  • 1965-06-12 DE DE1483641A patent/DE1483641C3/de not_active Expired
• 1966
  • 1966-06-01 US US554331A patent/US3407864A/en not_active Expired - Lifetime
  • 1966-06-06 GB GB25137/66A patent/GB1073676A/en not_active Expired

Patent Citations (7)

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