Electrodeposition whetstone and manufacturing method

Abstract

According to an embodiment, an electrodeposition whetstone includes a plating layer, first abrasive grains protruding from the plating layer, and second abrasive grains which are arranged between the first abrasive grains. The amount of protrusion of the second abrasive grains from the plating layer is smaller than the amount of protrusion of the first abrasive grains from the plating layer. A grain size of the second abrasive grains is smaller than a grain size of the first abrasive grains.

What is claimed is: 
     
         1 . An electrodeposition whetstone comprising:
 a plating layer;   a base on which the plating layer is provided;   first abrasive grains protruding from the plating layer; and   second abrasive grains arranged between the first abrasive grains,
 the amount of protrusion of the second abrasive grains from the plating layer being smaller than the amount of protrusion of the average grain size of the first abrasive grains from the plating layer, and 
 a grain size of the second abrasive grains being smaller than a grain size of the first abrasive grains, 
   wherein:   the plating layer includes a first plating layer provided on the base and a second plating layer provided on the first plating layer,   the electrodeposition whetstone includes:   a first virtual plane formed by a plurality of protruding ends of the first abrasive grains, and   a second virtual plane formed by a plurality of protruding ends of the second abrasive grains,   the first virtual plane is located outside with respect to the second virtual plane,   a distance between the first virtual plane and the second virtual plane is equal to or smaller than a range determined based at least on the average grain size of the first abrasive grains, the average grain size of the second abrasive grains, and a thickness of the plating layer, and   the range increases as a thickness of the first plating layer increases.   
     
     
         2 . The electrodeposition whetstone according to  claim 1 , wherein:
 a grain size of the first abrasive grains is 25 μm or larger and 300 μm or smaller,   a grain size of the second abrasive grains is 10 μm or larger and 120 μm or smaller,   the thickness of the plating layer is 40% or larger and 80% or smaller of the average grain size of the first abrasive grains, and   the range is 6 μm or larger and 42 μm or smaller.   
     
     
         3 . The electrodeposition whetstone according to  claim 1 , wherein:
 the first abrasive grains are separated from each other, and   the second abrasive grains are respectively arranged in a gap between the first abrasive grains.   
     
     
         4 . The electrodeposition whetstone according to  claim 3 , wherein a size of the gap between the first abrasive grains is 20 μm or larger. 
     
     
         5 . The electrodeposition whetstone according to  claim 1 , wherein:
 lower ends of the first abrasive grains are at a boundary between the base and the first plating layer, and   lower ends of the second abrasive grains are at a boundary between the first plating layer and the second plating layer.   
     
     
         6 . The electrodeposition whetstone according to  claim 1 , wherein:
 the first abrasive grains include at least one selected from a group consisting of diamond abrasive grains, CBN abrasive grains, and metal oxide abrasive grains, and   the second abrasive grains include at least either one of diamond abrasive grains and CBN abrasive grains.   
     
     
         7 . The electrodeposition whetstone according to  claim 1 , wherein the plating layer includes at least one selected from a group consisting of polytetrafluoroethylene and tungsten. 
     
     
         8 . A manufacturing method comprising:
 securing a plurality of first abrasive grains to a base by a first plating layer, with gaps formed between the first abrasive grains, and forming a first virtual plane by a plurality of protruding ends of the first abrasive grains;   arranging second abrasive grains in the gaps, a grain size of the second abrasive grains being smaller than a grain size of the first abrasive grains; and   securing the first abrasive grains and the second abrasive grains by second plating different from the first plating layer in such a manner that the amount of protrusion of the second abrasive grains is smaller than the amount of protrusion of the first abrasive grains, forming a plating layer from the first plating layer and the second plating layer, and forming a second virtual plane by a plurality of protruding ends of the second abrasive grains,   wherein:   an average distance between the first virtual plane and the second virtual plane is equal to or smaller than a range determined based at least on an average grain size of the first abrasive grains, an average grain size of the second abrasive grains, and a thickness of the plating layer, and   the range increases as a thickness of the first plating layer increases.   
     
     
         9 . The manufacturing method according to  claim 8 , wherein:
 the first plating layer is electrolytic plating, and   the second plating layer is electroless plating.   
     
     
         10 . The manufacturing method according to  claim 9 , further comprising:
 separating the first abrasive grains from each other, and   arranging the second abrasive grains in the gaps between the first abrasive grains.   
     
     
         11 . The manufacturing method according to  claim 8 , wherein the second plating layer contains at least one selected from a group consisting of polytetrafluoroethylene and tungsten.