Sheet Material Infiltration of Powder Metal Parts

Abstract

A powder metal part infiltration process uses a stamped metallic sheet as a source of metal for infiltration to achieve a high strength powder metal part. A powder metal is compacted, and an infiltrant blank is formed from a wrought metal sheet. The infiltrant blank is placed on top of the compact, and the compact is sintered at a temperature sufficient to form a sintered compact with a matrix having pores and to melt the wrought metal such that the melted wrought metal infiltrates the pores of the matrix. The infiltrant blank may be formed with a locating element for engaging a corresponding locating element on the compact to improve positioning of the blank on the compact. Also, the compact may be separately sintered, and the infiltrant blank may then be placed on the sintered compact. The wrought metal is then melted such that the melted wrought metal infiltrates the pores of the matrix.

1 . A process for manufacturing a metal-infiltrated powder metal part, the process comprising:
 compacting a powder metal to form a compact;   forming an infiltrant blank from a wrought metal sheet;   placing the infiltrant blank on top of the compact; and   sintering the compact at a temperature sufficient to form a sintered compact with a matrix having pores and to melt the wrought metal such that the melted wrought metal infiltrates the pores of the matrix.   
     
     
         2 . The process of  claim 1  wherein:
 the powder metal is selected from iron, iron alloys and mixtures thereof; and   the wrought metal is selected from copper and copper alloys.   
     
     
         3 . The process of  claim 2  wherein:
 the wrought metal sheet has a thickness of less than 1 millimeter.   
     
     
         4 . The process of  claim 1  wherein:
 the infiltrant blank is formed by a method selected from stamping, fine blanking and abrasive water jet cutting.   
     
     
         5 . The process of  claim 1  further comprising:
 forming the infiltrant blank with a locating element that is suitable for engaging a corresponding locating element on the compact; and   placing the infiltrant blank in contact with the compact such that the locating element of the blank engages the corresponding locating element on the compact.   
     
     
         6 . The process of  claim 5  wherein:
 the locating element of the blank is a section of the blank extending outwardly from a body of the blank.   
     
     
         7 . A process for manufacturing a metal-infiltrated powder metal part, the process comprising:
 compacting a powder metal to form a compact;   sintering the compact at a temperature sufficient to form a sintered compact with a matrix having pores;   forming an infiltrant blank from a wrought metal sheet;   placing the infiltrant blank on top of the sintered compact; and   melting the wrought metal such that the melted wrought metal infiltrates the pores of the matrix.   
     
     
         8 . The process of  claim 7  wherein:
 the powder metal is selected from iron, iron alloys and mixtures thereof; and   the wrought metal is selected from copper and copper alloys.   
     
     
         9 . The process of  claim 8  wherein:
 the wrought metal sheet has a thickness of less than 1 millimeter.   
     
     
         10 . The process of  claim 7  wherein:
 the infiltrant blank is formed by a method selected from stamping, fine blanking and laser cutting.   
     
     
         11 . The process of  claim 7  further comprising:
 forming the infiltrant blank with a locating element that is suitable for engaging a corresponding locating element on the compact; and   placing the infiltrant blank in contact with the compact such that the locating element of the blank engages the corresponding locating element on the compact.   
     
     
         12 . The process of  claim 7  wherein:
 the locating element of the blank is a section of the blank extending outwardly from a body of the blank.   
     
     
         13 . A process for manufacturing a metal-infiltrated powder metal part, the process comprising:
 compacting a powder metal to form a compact;   forming an infiltrant blank from a wrought metal sheet, the blank having a locating element that is suitable for engaging a corresponding locating element on the compact;   placing the infiltrant blank in contact with the compact such that the locating element of the blank engages the corresponding locating element on the compact; and   sintering the compact at a temperature sufficient to form a sintered compact with a matrix having pores and to melt the wrought metal such that the melted wrought metal infiltrates the pores.   
     
     
         14 . The process of  claim 13  wherein:
 the powder metal is selected from iron, iron alloys and mixtures thereof; and   the wrought metal is selected from copper and copper alloys.   
     
     
         15 . The process of  claim 14  wherein:
 the wrought metal sheet has a thickness of less than 1 millimeter.   
     
     
         16 . The process of  claim 13  wherein:
 the infiltrant blank is formed by a method selected from stamping, fine blanking and laser cutting.   
     
     
         17 . The process of  claim 13  wherein:
 the locating element of the blank is a section of the blank extending outwardly from a body of the blank.   
     
     
         18 . A process for manufacturing a metal-infiltrated powder metal part, the process comprising:
 compacting a powder metal to form a compact;   sintering the compact at a temperature sufficient to form a sintered compact with a matrix having pores;   forming an infiltrant blank from a wrought metal sheet, the blank having a locating element that is suitable for engaging a corresponding locating element on the sintered compact;   placing the infiltrant blank in contact with the sintered compact such that the locating element of the blank engages the corresponding locating element on the sintered compact; and   melting the wrought metal such that the melted wrought metal infiltrates the pores of the sintered compact.   
     
     
         19 . The process of  claim 18  wherein:
 the powder metal is selected from iron, iron alloys and mixtures thereof; and   the wrought metal is selected from copper and copper alloys.   
     
     
         20 . The process of  claim 19  wherein:
 the wrought metal sheet has a thickness of less than 1 millimeter.   
     
     
         21 . The process of  claim 18  wherein:
 the infiltrant blank is formed by a method selected from stamping, fine blanking and laser cutting.   
     
     
         22 . The process of  claim 18  wherein:
 the locating element of the blank is a section of the blank extending outwardly from a body of the blank.