Multiple-phase surfaces, and method therefor

Abstract

A workpiece having a multiple-phase working surface, and a lapping process for producing the surface, the process including: (a) providing a system including: (i) a workpiece having a multiple-phase working surface having a first continuous solid phase, and a second solid phase, intimately dispersed within the continuous phase in the multiple-phase working surface, she continuous phase having a hastiness exceeding a hardness of the second phase by a Mohs Hardness of at least 0.5; (ii) a contact surface, disposed generally opposite the working surface, having a Shore D hardness within a range of 40-90, and a Young's modulus of less than 20 gigapascels; (iii) a plurality of abrasive particles, freely disposed between the contact and working surfaces, and (b) lapping the working surface by exerting a pressure on the surfaces and applying a relative motion between the surfaces, to effect an elastic interaction between the contact surface and the abrasive particles in which at least a portion of the abrasive particles penetrate the working surface, to produce a lapped product having a modified working surface, in which an exterior surface of the second phase is recessed by an average of at least 1.5 micrometers with respect to an exterior surface of the continuous phase.

What is claimed is: 
     
         1 . A workpiece comprising: a multiple-phase working surface including: (A) a first continuous solid phase; (B) a second solid phase, intimately dispersed within said continuous phase in said multiple-phase working surface, said continuous phase having a hardness exceeding a hardness of said second phase by a Mohs Hardness of at least 0.5, and in which said second phase is a recessed phase having an exterior surface that is recessed by an average of at least 1.5 micrometers with respect to an exterior surface of said continuous phase. 
     
     
         2 . The workpiece of  claim 1 , wherein said continuous phase has a hardness exceeding a hardness of said second phase by a Mobs Hardness of at least 1.0. 
     
     
         3 . The workpiece of  claim 1 , wherein said continuous phase has a hardness exceeding a hardness of said second phase by a Mobs Hardness of at least 2.5. 
     
     
         4 . The workpiece of  claim 1 , wherein said continuous phase has a hardness exceeding a hardness of said second phase by a Mobs Hardness of at least 3.5. 
     
     
         5 . The workpiece of  claim 1 , wherein said continuous phase has a hardness exceeding a hardness of said second phase by a Mohs Hardness of 4 to 7. 
     
     
         6 . The workpiece of  claim 1 , wherein said continuous phase has a Mohs hardness of at least 2.5. 
     
     
         7 . The workpiece of claim I, wherein said continuous phase has a Mohs hardness of at least 3.5. 
     
     
         8 . The workpiece of  claim 1 , wherein said continuous phase has a Mohs hardness of at least4.5. 
     
     
         9 . The workpiece of  claim 1 , wherein said continuous phase has a Mobs hardness of 6 to 8. 
     
     
         10 . The workpiece of  claim 1 , wherein said second phase has a Mohs hardness of 1 to 2. 
     
     
         11 . The workpiece of  claim 1 , wherein said multiple-phase working surface includes a cast-iron surface, wherein the continuous phase has a surface roughness, (R a ), of less than 0.5 micrometers. 
     
     
         12 . The workpiece of  claim 1 , wherein said multiple-phase working surface includes a cast-iron surface, said continuous solid phase includes ferrite and said second phase includes graphite. 
     
     
         13 . The workpiece of  claim 12 , wherein the graphite of said second phase is laminar graphite. 
     
     
         14 . The workpiece of  claim 12 , wherein the graphite of said second phase is spheroidal graphite. 
     
     
         15 . The workpiece of  claim 12 , wherein a plurality of inorganic particles are incorporated in said continuous phase, said inorganic particles having a Mohs hardness of at least 8 and wherein a surface of said plurality of particles is at least partially covered with a solid catalyst. 
     
     
         16 . The workpiece of  claim 15 , wherein the solid catalyst is a photovoltaic solid. 
     
     
         17 . The workpiece of  claim 16 , wherein the photovoltaic solid is silicon or gallium arsenide. 
     
     
         18 . The workpiece of  claim 15 , wherein said inorganic particles have a population density of at least 10,000 particles per square millimeter. 
     
     
         19 . The workpiece of  claim 1 , wherein a plurality of inorganic particles are incorporated in said continuous phase, said inorganic particles having a Mohs hardness of at least 8, and wherein a surface of said plurality of particles is at least partially covered with an anti-microbial solid. Fix numbering 
     
     
         20 . The workpiece of  claim 2 , wherein the workpiece and said multiple-phase working surface satisfy a relationship:
   A s(soft) =KV s(soft) ,   wherein: A s(soft)  is a specific nominal surface area of said second solid phase on said working surface; K is a coefficient; V s(soft)  is a volume fraction of said second solid phase, defined by:
   V s(soft) =W s(soft) /ρ s(soft) ,
 
   wherein: ρ s(soft)  is a density of said second phase, in grams per cubic centimeter;   W s(soft)  is a weight of said second phase per unit volume of the workpiece, in grams per cubic centimeter of the workpiece; and wherein said coefficient K is at least 0.6.   
     
     
         21 . The workpiece of  claim 20 , wherein said coefficient K is at least 0.7. 
     
     
         22 . The workpiece of  claim 20 , wherein said coefficient K is at least 0.8. 
     
     
         23 . The workpiece of  claim 20 , wherein said coefficient K is at least 0.9. 
     
     
         24 . The workpiece of  claim 2 , wherein the workpiece and said multiple-phase working surface satisfy a relationship: K I(soft) =S exposed /S max  wherein: S exposed  is an exposed nominal surface area of a particular particle of a plurality of particles of said second solid phase on said multiple-phase working surface, and S max  is a maximum nominal cross-sectional area of said particular particle, for cross-sections that are nominally parallel to said multiple-phase working surface, K I(soft)  is a ratio of S exposed  to S max , and wherein, for at least 50% of said plurality of particles of said second solid phase said ratio is at least equal to 0.8. 
     
     
         25 . The workpiece of  claim 2 , wherein a plurality of inorganic particles are incorporated in said continuous phase, said inorganic particles having a Mohs hardness of at least 8. 
     
     
         26 . The workpiece of  claim 25 , wherein a surface of said plurality of particles is at least partially coated with an organic polymer. 
     
     
         27 . The workpiece of  claim 26 , wherein said inorganic particles have a population density of at least 10,000 particles per square millimeter. 
     
     
         28 . The workpiece of  claim 1 , wherein the workpiece and said multiple-phase working surface satisfy a relationship: K I(soft) =S exposed /S max  wherein: S exposed  is an exposed nominal surface area of a particular particle of a plurality of particles of said second solid phase on said multiple-phase working surface, and S max  is a maximum nominal cross-sectional area of said particular particle, for cross-sections that are nominally parallel to said multiple-phase working surface, K I(soft)  is a ratio of S exposed  to S max , and wherein, for at least 50% of said plurality of particles of said second solid phase said ratio is at least equal to 0.8. 
     
     
         29 . The workpiece of  claim 1 , wherein a plurality of inorganic particles are incorporated in said continuous phase, said inorganic particles having a Mohs hardness of at least 8 and population density of at least 10,000 particles per square millimeter. 
     
     
         30 . The workpiece of  claim 1 , wherein the second phase has a rounded shoulder between the continuous phase and an exposed surface of the second phase. 
     
     
         31 . The workpiece of  claim 1 , wherein the second phase has a rounded shoulder between a plastic deformation zone of the continuous phase and an exposed surface of the second phase. 
     
     
         32 . A lapping process for producing a modified multiple-phase working surface from a multiple-phase working surface, the process comprising the steps of:
 (a) providing a system including:
 (i) a workpiece having a multiple-phase working surface including:
 (A) a first continuous solid phase; 
 (B) a second solid phase, intimately dispersed within said continuous phase in said multiple-phase working surface, 
 
   said continuous phase having a hardness exceeding a hardness of said second phase by a Mohs Hardness of at least 0.5;
 (ii) a contact surface, disposed generally opposite said working surface, said contact surface having a Shore D hardness within a range of 40-90, and a Young's modulus of less than 20 gigapascals (GPa); 
 (iii) a plurality of particles, including abrasive particles, said plurality of particles freely disposed between said contact surface and said working surface, and 
   (b) lapping said multiple-phase working surface by exerting a pressure on said contact surface and said multiple-phase working surface, and applying a relative motion between said working surface and said contact surface, to effect an at least partially elastic interaction between said contact surface and said abrasive particles in which at least a portion of said abrasive particles penetrate said working surface, to produce a lapped product having the modified multiple-phase working surface, in which an exterior surface of said second phase is recessed by an average of at least 1.5 micrometers with respect to an exterior surface of said continuous phase, the workpiece having the multiple-phase working surface including at a time prior to initiation of the exerting of pressure on said multiple-phase working surface and on said contact surface,   wherein said exerting said pressure and applying said relative motion, a temperature at said contact surface increases to at least 35 degrees C.