SAW WIRE AND METHOD OF MANUFACTURING SAW WIRE
There are provided a fixed-abrasive grain saw wire with a superior cutting performance and a manufacturing method thereof. Particularly, there are provided a fixed-abrasive grain saw wire with abrasive grains adhered to a metal wire via a Zn-based or Sn-based low-melting-point metal and a high-melting-point metal having a melting point higher than that of the low-melting-point metal, and a manufacturing method thereof.
1 . A fixed-abrasive grain saw wire with abrasive grains adhered to a metal wire through an adhesion portion, wherein said adhesion portion includes:
a Zn-based or Sn-based low-melting-point metal; and
a high-melting-point metal with a melting point higher than that of said low-melting-point metal, wherein said low-melting-point metal contains at least precipitates of said high-melting-point metal.
2 . The saw wire according to claim 1 , wherein said high-melting-point metal is contained in a high-melting-point metal layer formed on at least one of areas including peripheries of said abrasive grains, a surface of said saw wire and a surface of said metal wire.
3 . The saw wire according to claim 1 , wherein said abrasive grains are coated with a Ni coating layer, said low-melting-point metal is an Sn-based solder containing 0.5 to 5.0% by mass of Ag, and said high-melting-point metal is an intermetallic compound containing Sn.
4 . The saw wire according to claim 3 , wherein said Sn-based solder containing 0.5 to 5.0% by mass of Ag has a structure in which there are dispersed Ag 3 Sn-based intermetallic compounds that are at least one of a plate type having a thickness of 1 to 2 μm and a cord type having a diameter of 1 to 2 μm.
5 . The saw wire according to claim 3 , wherein said Sn-based solder containing 0.5 to 5.0% by mass of Ag further contains 0.01 to 0.5% by mass of Fe and 0.01 to 0.5% by mass of Ni.
6 . The saw wire according to claim 3 , wherein said abrasive grains comprise a multi-layered coating layer having a lower layer of Ti or Cr and an upper layer of Ni.
7 . The saw wire according to claim 3 , wherein said intermetallic compound containing Sn exists at least around said abrasive grains.
8 . The saw wire according to claim 2 , wherein an intermetallic compound containing Sn and Ni exists as an intermetallic compound layer around said abrasive grains.
9 . The saw wire according to claim 2 , wherein an intermetallic compound containing Sn and Ni includes one or more than one of Ni 3 SN 4 , Ni 3 Sn 2 and Sn (1-x-y) Ni x Cu y (here, 0.1≦x≦0.7, 0.01≦y≦0.5)
10 . The saw wire according to claim 1 , wherein said low-melting-point metal is a solder containing Sn and Zn, and said high-melting-point metal is an intermetallic compound containing Sn or Zn.
11 . The saw wire according to claim 10 , wherein said solder has a Zn content of 1 to 35% by mass.
12 . The saw wire according to claim 11 , wherein said solder has a composition represented by Sn—Zn—X in which X includes one or more than one of Bi, Ni, Cu, Fe, Sb, Pb, In and Ag, and a content of X is 0.5 to 5% by mass.
13 . The saw wire according to claim 10 , wherein said abrasive grains are coated with a Ni or Cu coating layer.
14 . The saw wire according to claim 10 , wherein said abrasive grains comprise a multi-layered coating layer having a lower layer of Ti or Cr and an upper layer of Ni or Cu.
15 . The saw wire according to claim 10 , wherein said intermetallic compound containing Sn or Zn exists at least around said abrasive grains.
16 . The saw wire according to claim 10 , wherein said intermetallic compound containing Sn or Zn includes one or more than one of a Ni—Sn-based, a Ni—Zn-based, a Ni—Sn—Zn-based, a Cu—Sn-based, a Cu—Sn—Zn-based and a Cu—Zn-based intermetallic compounds.
17 . The saw wire according to claim 1 , wherein said adhesion portion includes
a high-melting-point metal layer composed of said high-melting-point metal with a melting point of 700° C. or higher; and
a low-melting-point metal layer composed of said low-melting-point metal.
18 . The saw wire according to claim 17 , wherein said high-melting-point metal layer is formed on an outside of said low-melting-point metal layer.
19 . The saw wire according to claim 17 , wherein said high-melting-point metal composing said high-melting-point metal layer and said low-melting-point metal composing said low-melting-point metal layer are diffused with one another, thereby forming in said low-melting-point metal layer an alloy phase of said low-melting-point metal and said high-melting-point metal.
20 . The saw wire according to claim 17 , wherein said high-melting-point metal composing said high-melting-point metal layer is Ni or a Ni alloy, or Cu or a Cu alloy.
21 . The saw wire according to claim 17 , wherein said abrasive grains have a Ni coating layer.
22 . The saw wire according to claim 17 , wherein said low-melting-point metal layer is formed through hot-dip plating.
23 . The saw wire according to claim 17 , wherein said low-melting-point metal composing said low-melting-point metal layer is a Zn—Al alloy.
24 . The saw wire according to claim 1 , wherein said abrasive grains are diamond abrasive grains.
25 . The saw wire according to claim 1 , wherein said metal wire is a steel wire.
26 . The saw wire according to claim 25 , wherein the surface of said metal wire is coated with a plating layer of Zn, brass or Cu.
27 . A manufacturing method of saw wire for manufacturing a fixed-abrasive grain saw wire with a plurality of abrasive grains adhered to a metal wire, comprising:
mixing said abrasive grains into a molten metal bath prepared by melting a low-melting-point metal:
dipping said metal wire into said molten metal bath, followed by continuously pulling up said metal wire in a substantially vertical direction, thereby allowing said abrasive grains to be adhered to said metal wire.
28 . The manufacturing method of saw wire according to claim 27 , wherein said metal wire is continuously pulled up while said molten metal bath is being stirred or oscillated.
29 . The manufacturing method of saw wire according to claim 27 , wherein said low-melting-point metal is Sn or an Sn alloy, or Zn or a Zn alloy.
30 . The manufacturing method of saw wire according to claim 27 , wherein said metal wire is coated with a high-melting-point metal layer.
31 . The manufacturing method of saw wire according to claim 27 , wherein after said abrasive grains are adhered through said low-melting-point metal, a high-melting-point metal layer is formed thereon.
32 . The manufacturing method of saw wire according to claim 30 , comprising forming a diffused layer of a low-melting-point metal composing a low-melting-point metal layer and a high-melting-point metal composing a high-melting-point metal layer by performing a heating treatment at a temperature of not lower than 200° C. and not higher than 600° C. after forming said high-melting-point metal layer.
33 . The manufacturing method of saw wire according to claim 30 , wherein a high-melting-point metal composing said high-melting-point metal layer is Ni or an Ni alloy, or Cu or a Cu alloy.