Patent Description:
Tools necessary for furthering infrastructure improvements, such as building additional roads and buildings, are vital to the continued economic expansion of developing regions. Additionally, developed regions have a continuing need to replacing aging infrastructure with new and expanded roads and buildings.

The construction industry utilizes a variety of tools for cutting and grinding of construction materials. Cutting and grinding tools are required for to remove or refinish old sections of roads. Additionally, quarrying and preparing finishing materials, such as stone slabs used for floors and building facades, require tools for drilling, cutting, and polishing. Typically, these tools include abrasive segments bonded to a base element or core, such as a plate or a wheel. As with other industries, improvements to these abrasive tools are always sought.

<CIT> relates to a cutting wheel, comprising a disk-shaped abrasive body having two opposite faces and a non-uniform thickness. The faces may be shaped, for example, to define a plurality of zigzag profiles, extending along respective broken lines arranged in succession over an annular band.

<CIT> discloses diamond abrasive cutoff blades, the segments thereof characterized by their cutting surfaces having substantially uniform linear or lateral serrations.

Subject matter of the present invention is an abrasive article as defined in claim <NUM>. The dependent claims relate to particular embodiments thereof.

According to an embodiment, the abrasive article herein includes a core and a plurality of abrasive segments affixed to the core. The abrasive article can be a grinding tool for grinding metal, concrete, or natural stone.

In general, the abrasive article includes multiple Z-shaped segments affixed to a core. <FIG> and <FIG> illustrate an exemplary abrasive article designated <NUM>. <FIG> includes a front plan view of the abrasive article <NUM>. <FIG> includes a rear plan view of the abrasive article <NUM>. <FIG> include various views of a shaped segment that can be installed on the core. Specifically, <FIG> includes a front plan view of the segment. <FIG> includes a rear plan view of the segment. <FIG> includes a left side plan view. <FIG> includes a right side plan view. <FIG> includes a top plan view and <FIG> includes a bottom plan view of the segment. <FIG> includes an enlarged bottom plan view of the segment.

<FIG> and <FIG> illustrates an exemplary abrasive article designated <NUM>. As depicted, the abrasive article <NUM> can include a generally cup-shaped core <NUM>. The core <NUM> can include a body <NUM> having a generally disc-shaped central hub <NUM> formed with a central bore <NUM> along a center <NUM> of the core <NUM>. The center <NUM> of the core <NUM> is also the center <NUM> of the abrasive article <NUM>.

A generally frusto-conical sidewall <NUM> can extend radially outward and axially from the central hub <NUM> at an angle with respect to the central hub <NUM>. The sidewall <NUM> can include a distal end <NUM> and a generally ring-shaped segment support flange <NUM> can extend radially outward from the distal end <NUM> of the frusto-conical sidewall <NUM>. The segment support flange <NUM> can include a face <NUM> perpendicular to a direction of rotation of the abrasive article <NUM> around a central axis passing perpendicularly through the center <NUM> of the abrasive article <NUM>.

A plurality of abrasive segments <NUM> affixed to the face <NUM> of the segment support flange <NUM> can extend axially away from the segment support flange <NUM> in a direction parallel to the central axis. The segments <NUM> can be formed separately from the core <NUM>, as described herein, and affixed to the core via a brazing procedure, a welding procedure, a mechanical coupling, etc. In a particular aspect, each adjacent pair of segments <NUM> can be separated by a gap <NUM>. According to the present invention, the segments (<NUM>) include a plurality of outer peripheral serrations (<NUM>) formed in an outer circumferential wall (<NUM>) of the segment.

<FIG> illustrate the details of one of the segments <NUM>. As illustrated, the segment <NUM> can include a body <NUM> that can include a generally curved inner segment portion <NUM> and a generally curved outer segment portion <NUM> spaced a radial distance, d, from the inner segment portion <NUM>. The body <NUM> of the segment <NUM> can also include a central segment portion <NUM> connected to the inner segment portion <NUM> and the outer segment portion <NUM>.

In a particular aspect, the inner segment portion <NUM> can include an inner circumferential wall <NUM> and an outer circumferential wall <NUM>. The inner segment portion <NUM> can also include a leading radial sidewall <NUM> extending between the inner circumferential wall <NUM> and the outer circumferential wall <NUM> and a trailing radial sidewall <NUM> extending between the inner circumferential wall <NUM> and the outer circumferential wall <NUM> opposite the leading radial sidewall <NUM>. The terms leading and trailing, as used herein, can be defined based on a direction of rotation of the abrasive article <NUM>, which is counterclockwise in the view illustrated in <FIG>.

As illustrated, the inner segment portion <NUM> can further include a first grinding face <NUM> that can extend between the inner and outer circumferential walls <NUM>, <NUM> and the leading and trailing radial sidewalls <NUM>, <NUM>. Moreover, a first serrated portion <NUM> can extend at least partially over the first grinding face <NUM>. In a particular aspect, the first grinding face <NUM> can include an area, AGF1, and the first serrated portion <NUM> can include an area, ASP1. ASP1 can be < AGF1. For example, ASP1 can be ≤ <NUM>% AGF1, such as ≤ <NUM>% AGF1, ≤ <NUM>% AGF1, ≤ <NUM>% AGF1, or < <NUM>% AGF1. Further, ASP1 can be ≥ <NUM>% AGF1, such as ≥ <NUM>% AGF1, ≥ <NUM>% AGF1, ≥ <NUM>% AGF1, or ≥ <NUM>% AGF1. In another aspect, ASP1 can be within a range between and including any of the maximum and minimum values of ASP1 described herein.

For example, ASP1 can be ≤ <NUM>% AGF1 and ≥ <NUM>% AGF1, such as ≤ <NUM>% AGF1 and ≥ <NUM>% AGF1, ≤ <NUM>% AGF1 and ≥ <NUM>% AGF1, ≤ <NUM>% AGF1 and ≥ <NUM>% AGF1, or ≤ <NUM>% AGF1 and ≥ <NUM>% AGF1. ASP1 can be ≤ <NUM>% AGF1 and ≥ <NUM>% AGF1, such as ≤ <NUM>% AGF1 and ≥ <NUM>% AGF1, ≤ <NUM>% AGF1 and ≥ <NUM>% AGF1, ≤ <NUM>% AGF1 and ≥ <NUM>% AGF1, or ≤ <NUM>% AGF1 and ≥ <NUM>% AGF1. ASP1 can be ≤ <NUM>% AGF1 and ≥ <NUM>% AGF1, such as ≤ <NUM>% AGF1 and ≥ <NUM>% AGF1, ≤ <NUM>% AGF1 and ≥ <NUM>% AGF1, ≤ <NUM>% AGF1 and ≥ <NUM>% AGF1, or ≤ <NUM>% AGF1 and ≥ <NUM>% AGF1. Further, ASP1 can be ≤ <NUM>% AGF1 and ≥ <NUM>% AGF1, such as ≤ <NUM>% AGF1 and ≥ <NUM>% AGF1, ≤ <NUM>% AGF1 and ≥ <NUM>% AGF1, < <NUM>% AGF1 and ≥ <NUM>% AGF1, or < <NUM>% AGF1 and ≥ <NUM>% AGF1. Still further, ASP1 can be ≤ <NUM>% AGF1 and ≥ <NUM>% AGF1, such as ≤ <NUM>% AGF1 and ≥ <NUM>% AGF1, ≤ <NUM>% AGF1 and ≥ <NUM>% AGF1, ≤ <NUM>% AGF1 and ≥ <NUM>% AGF1, or ≤ <NUM>% AGF1 and ≥ <NUM>% AGF1.

In a particular aspect, the inner segment portion <NUM> can have a first radial width, W<NUM>, measured from the inner circumferential wall <NUM> to the outer circumferential wall <NUM>. W<NUM> can be ≥ d, described above. For example, W<NUM> can be ≥ <NUM>% d, such as ≥ <NUM>% d, or ≥ <NUM>% d. In another aspect, W<NUM> can be ≤ <NUM>% d, such as ≤ <NUM>% d, or ≤ <NUM>% d. W<NUM> can also be within a range between and including any of the maximum and minimum values of W<NUM> described herein.

For example, W<NUM> can be ≥ <NUM>% d and ≤ <NUM>% d, such as ≥ <NUM>% d and ≤ <NUM>% d, or ≥ <NUM>% d and ≤ <NUM>% d. Further, W<NUM> can be ≥ <NUM>% d and ≤ <NUM>% d, such as ≥ <NUM>% d and ≤ <NUM>% d, or ≥ <NUM>% d and ≤ <NUM>% d. Still further, W<NUM> can be ≥ <NUM>% d and ≤ <NUM>% d, such as ≥ <NUM>% d and ≤ <NUM>% d, or ≥ <NUM>% dand ≤ <NUM>% d.

As illustrated, the outer segment portion <NUM> can include an inner circumferential wall <NUM> and an outer circumferential wall <NUM>. The outer segment portion <NUM> can also include a leading radial sidewall <NUM> extending between the inner circumferential wall <NUM> and the outer circumferential wall <NUM> and a trailing radial sidewall <NUM> extending between the inner circumferential wall <NUM> and the outer circumferential wall <NUM> opposite the leading radial sidewall <NUM>.

As illustrated, the outer segment portion <NUM> can further include a second grinding face <NUM> that can extend between the inner and outer circumferential walls <NUM>, <NUM> and the leading and trailing radial sidewalls <NUM>, <NUM>. Moreover, a second serrated portion <NUM> can extend at least partially over the second grinding face <NUM>. In a particular aspect, the second grinding face <NUM> can include an area, AGF2, and the second serrated portion <NUM> can include an area, ASP2. ASP2 can be < AGF2. For example, ASP2 can be ≤ <NUM>% AGF2, such as ≤ <NUM>% AGF2, ≤ <NUM>% AGF2, < <NUM>% AGF2, or ≤ <NUM>% AGF2. Further, ASP2 can be ≥ <NUM>% AGF2, such as ≥ <NUM>% AGF2, ≥ <NUM>% AGF2, ≥ <NUM>% AGF2, or ≥ <NUM>% AGF2. In another aspect, ASP2 can be within a range between and including any of the maximum and minimum values of ASP2 described herein.

For example, ASP2 can be ≤ <NUM>% AGF2 and ≥ <NUM>% AGF2, such as ≤ <NUM>% AGF2 and ≥ <NUM>% AGF2, ≤ <NUM>% AGF2 and ≥ <NUM>% AGF2, ≤ <NUM>% AGF2 and ≥ <NUM>% AGF2, or ≤ <NUM>% AGF2 and ≥ <NUM>% AGF2. ASP2 can be ≤ <NUM>% AGF2 and ≥ <NUM>% AGF2, such as ≤ <NUM>% AGF2 and ≥ <NUM>% AGF2, ≤ <NUM>% AGF2 and ≥ <NUM>% AGF2, ≤ <NUM>% AGF2 and ≥ <NUM>% AGF2, or ≤ <NUM>% AGF2 and ≥ <NUM>% AGF2. ASP2 can be ≤ <NUM>% AGF2 and ≥ <NUM>% AGF2, such as ≤ <NUM>% AGF2 and ≥ <NUM>% AGF2, ≤ <NUM>% AGF2 and ≥ <NUM>% AGF2, ≤ <NUM>% AGF2 and ≥ <NUM>% AGF2, or ≤ <NUM>% AGF2 and ≥ <NUM>% AGF2. Further, ASP2 can be ≤ <NUM>% AGF2 and ≥ <NUM>% AGF2, such as ≤ <NUM>% AGF2 and ≥ <NUM>% AGF2, ≤ <NUM>% AGF2 and ≥ <NUM>% AGF2, ≤ <NUM>% AGF2 and ≥ <NUM>% AGF2, or ≤ <NUM>% AGF2 and ≥ <NUM>% AGF2. Still further, ASP2 can be ≤ <NUM>% AGF2 and > <NUM>% AGF2, such as ≤ <NUM>% AGF2 and ≥ <NUM>% AGF2, ≤ <NUM>% AGF2 and ≥ <NUM>% AGF2, ≤ <NUM>% AGF2 and ≥ <NUM>% AGF2, or ≤ <NUM>% AGF2 and ≥ <NUM>% AGF2.

In a particular aspect, the outer segment portion <NUM> can have a second radial width, W<NUM>, measured from the inner circumferential wall <NUM> to the outer circumferential wall <NUM>. W<NUM> can be ≥ d, described above. For example, W<NUM> can be ≥ <NUM>% d, such as ≥ <NUM>% d, or ≥ <NUM>% d. In another aspect, W<NUM> can be ≤ <NUM>% d, such as ≤ <NUM>% d, or ≤ <NUM>% d. W<NUM> can also be within a range between and including any of the maximum and minimum values of W<NUM> described herein.

For example, W<NUM> can be ≥ <NUM>% d and ≤ <NUM>% d, such as ≥ <NUM>% d and ≤ <NUM>% d, or ≥ <NUM>% d and ≤ <NUM>% d. Further, W<NUM> can be ≥ <NUM>% d and ≤ <NUM>% d, such as ≥ <NUM>% d and ≤ <NUM>% d, or ≥ <NUM>% d and ≤ <NUM>% d. Still further, W<NUM> can be ≥ <NUM>% d and ≤ <NUM>% d, such as ≥ <NUM>% d and ≤ <NUM>% d, or ≥ <NUM>% d and ≤ <NUM>% d.

In another aspect, ASP1 can be ≤ ASP2. For example, ASP1 can be ≤ <NUM>% ASP2, such as ≤ <NUM>% ASP2, ≤ <NUM>% ASP2, or ≤ <NUM>% ASP2. Further, ASP1 ≥ <NUM>% ASP2, such as ≥ <NUM>% ASP2, or ≥ <NUM>% ASP2. In another aspect, ASP1 can be within a range between and including any of the maximum and minimum values of ASP1 described herein.

For example, ASP1 can be ≤ <NUM>% ASP2 and ≥ <NUM>% ASP2, such as ≤ <NUM>% ASP2 and ≥ <NUM>% ASP2, or ≤ <NUM>% ASP2 and ≥ <NUM>% ASP2. ASP1 can be ≤ <NUM>% ASP2 and ≥ <NUM>% ASP2, such as ≤ <NUM>% ASP2 and ≥ <NUM>% ASP2, or ≤ <NUM>% ASP2 and ≥ <NUM>% ASP2. Further, ASP1 can be ≤ <NUM>% ASP2 and ≥ <NUM>% ASP2, such as ≤ <NUM>% ASP2 and ≥ <NUM>% ASP2, or ≤ <NUM>% ASP2 and ≥ <NUM>% ASP2. Moreover, ASP1 can be ≤ <NUM>% ASP2 and ≥ <NUM>% ASP2, such as ≤ <NUM>% ASP2 and ≥ <NUM>% ASP2, or ≤ <NUM>% ASP2 and ≥ <NUM>% ASP2.

As further depicted in <FIG>, the outer segment portion <NUM> can further include a plurality of outer peripheral serrations <NUM> formed in the outer circumferential wall <NUM> of the outer segment portion <NUM>. The outer peripheral serrations <NUM> can extend along the entire outer circumferential wall <NUM> from the leading radial sidewall <NUM> to the trailing radial sidewall <NUM> of the outer segment portion <NUM>. Moreover, the outer peripheral serrations <NUM> can form a sinusoidal wave structure along the outer circumferential wall <NUM>.

In a particular aspect, the outer circumferential wall <NUM> have a circumferential length, LOCW, and the sinusoidal wave structure can includes a wavelength, WLSWS. WLSWS can be ≤ <NUM>OCW, such as ≤ <NUM>OCW, ≤ <NUM>OCW, or ≤ <NUM>OCW. Further, WLSWS can be ≥ <NUM>OCW, such as ≥ <NUM>OCW, ≥ <NUM>OCW, ≥ <NUM>OCW, or ≥ <NUM>OCW. WLSWS can be within a range between and including any of the maximum and minimum values of WLSWS described herein.

For example, WLSWS can be ≤ <NUM>OCW and ≥ <NUM>OCW, such as ≤ <NUM>OCW and ≥ <NUM>OCW, ≤ <NUM>OCW and ≥ <NUM>OCW, ≤ <NUM>OCW and ≥ <NUM>OCW, or ≤ <NUM>OCW and ≥ <NUM>OCW. In another aspect, WLSWS can be ≤ <NUM>OCW and ≥ <NUM>OCW, such as ≤ <NUM>OCW and ≥ <NUM>OCW, ≤ <NUM>OCW and ≥ <NUM>OCW, ≤ <NUM>OCW and ≥ <NUM>OCW, or ≤ <NUM>OCW and ≥ <NUM>OCW. Further, WLSWS can be ≤ <NUM>OCW and ≥ <NUM>OCW, such as ≤ <NUM>OCW and ≥ <NUM>OCW, ≤ <NUM>OCW and ≥ <NUM>OCW, ≤ <NUM>OCW and ≥ <NUM>OCW, or ≤ <NUM>OCW and ≥ <NUM>OCW. Further still, WLSWS can be ≤ <NUM>OCW and ≥ <NUM>OCW, such as ≤ <NUM>OCW and ≥ <NUM>OCW, ≤ <NUM>OCW and ≥ <NUM>OCW, ≤ <NUM>OCW and ≥ <NUM>OCW, or ≤ <NUM>OCW and ≥ <NUM>OCW.

As illustrated in <FIG>, the central segment portion <NUM> can include a leading radial sidewall <NUM> that can extend from the outer circumferential wall <NUM> of the inner segment portion <NUM> to the inner circumferential wall <NUM> of the outer segment portion <NUM>. The central segment portion <NUM> can also include a trailing radial sidewall <NUM> that can extend from the outer circumferential wall <NUM> of the inner segment portion <NUM> to the inner circumferential wall <NUM> of the outer segment portion <NUM>. In a particular aspect, the leading radial sidewall <NUM> of the central segment portion <NUM> can establish an acute angle, α, with respect to the outer circumferential wall <NUM> of the inner segment portion <NUM> and an obtuse angle, β, with respect the inner circumferential wall <NUM> of the outer segment portion <NUM>.

In a particular aspect, α can be < <NUM>°, such as ≤ <NUM>°, ≤ <NUM>°, ≤ <NUM>°, or ≤ <NUM>°. Moreover, α can be ≥ <NUM>°, such as ≥ <NUM>°, ≥ <NUM>°, or ≥ <NUM>°. Further, α can be within a range between and including any of the values of α described herein. For example, α can be < <NUM>° and ≥ <NUM>°, such as < <NUM>° and ≥ <NUM>°, < <NUM>° and ≥ <NUM>°, or < <NUM>° and ≥ <NUM>°. Further, α can be ≤ <NUM>° and ≥ <NUM>°, such as ≤ <NUM>° and ≥ <NUM>°, ≤ <NUM>° and ≥ <NUM>°, or ≤ <NUM>° and ≥ <NUM>°. Additionally, α can be ≤ <NUM>° and ≥ <NUM>°, such as ≤ <NUM>° and ≥ <NUM>°, ≤ <NUM>° and ≥ <NUM>°, or ≤ <NUM>° and ≥ <NUM>°. In another aspect, α can be ≤ <NUM>° and ≥ <NUM>°, such as ≤ <NUM>° and ≥ <NUM>°, ≤ <NUM>° and ≥ <NUM>°, or ≤ <NUM>° and ≥ <NUM>°. Still further, α can be ≤ <NUM>° and ≥ <NUM>°, such as ≤ <NUM>° and ≥ <NUM>°, ≤ <NUM>° and ≥ <NUM>°, or ≤ <NUM>° and ≥ <NUM>°.

In another aspect, β can be > <NUM>°, such as ≥ <NUM>°, ≥ <NUM>°, ≥ <NUM>°, or ≥ <NUM>°. Moreover, β can be ≤ <NUM>°, such as ≤ <NUM>°, ≤ <NUM>°, or ≤ <NUM>°. In another aspect, β can be within a range between and including any of the maximum and minimum values of β described herein. For example, β can be > <NUM>° and ≤ <NUM>°, such as > <NUM>° and ≤ <NUM>°, > <NUM>° and ≤ <NUM>°, or > <NUM>° and ≤ <NUM>°. Additionally, β can be ≥ <NUM>° and ≤ <NUM>°, such as ≥ <NUM>° and ≤ <NUM>°, ≥ <NUM>° and ≤ <NUM>°, or ≥ <NUM>° and ≤ <NUM>°. Further, β can be ≥ <NUM>° and ≤ <NUM>°, such as ≥ <NUM>° and ≤ <NUM>°, ≥ <NUM>° and ≤ <NUM>°, or ≥ <NUM>° and ≤ <NUM>°. Further still, β can be ≥ <NUM>° and ≤ <NUM>°, such as ≥ <NUM>° and ≤ <NUM>°, ≥ <NUM>° and ≤ <NUM>°, or ≥ <NUM>° and ≤ <NUM>°. Even further, β can be ≥ <NUM>° and ≤ <NUM>°, such as ≥ <NUM>° and ≤ <NUM>°, ≥ <NUM>° and ≤ <NUM>°, or ≥ <NUM>° and ≤ <NUM>°.

As best indicated in <FIG>, each serrated portion <NUM>, <NUM> can include a plurality of serrations <NUM>. Each serration includes a leading edge <NUM>, a trailing edge <NUM>, and a ramped surface <NUM> extending there between. In particular, each ramped surface <NUM> can extend at an angle, γ, into the first grinding face <NUM> or the second grinding face <NUM> from the trailing edge <NUM> to the leading edge <NUM>. In a particular aspect, γ can be ≥ <NUM>°, such as ≥ <NUM>°, or ≥ <NUM>°. Further, γ can be ≤ <NUM>°, such as ≤ <NUM>°, or ≤ <NUM>°. In another aspect, γ can be within a range between and including any of the maximum and minimum values described herein.

For example, γ can be ≥ <NUM>° and ≤ <NUM>°, such as ≥ <NUM>° and ≤ <NUM>°, or ≥ <NUM>° and ≤ <NUM>°. Further, γ can be ≥ <NUM>° and ≤ <NUM>°, such as ≥ <NUM>° and ≤ <NUM>°, or ≥ <NUM>° and ≤ <NUM>°. Still further, γ can be ≥ <NUM>° and ≤ <NUM>°, such as ≥ <NUM>° and ≤ <NUM>°, or ≥ <NUM>° and ≤ <NUM>°.

In a particular aspect, the abrasive segment <NUM> can include a thickness, TAS, measured from a rear face to a front face, e.g., the first grinding face <NUM> or the second grinding face <NUM>. The trailing edge <NUM> of each serration <NUM> can extend a distance, DTES, out from the first grinding face <NUM> or the second grinding face <NUM> and measured perpendicular to the first grinding face <NUM> or the second grinding face <NUM> and DTES can be ≤ <NUM> TAS, such as ≤ <NUM> TAS, ≤ <NUM> TAS, or ≤ <NUM> TAS. Moreover, DTES can be ≥ <NUM> TAS, such as ≥ <NUM> TAS, ≥ <NUM> TAS, or ≥ <NUM> TAS. In another aspect, DTES can be within a range between and including any of the maximum or minimum values of DTES described herein.

For example, DTES can be ≤ <NUM> TAS and ≥ <NUM> TAS, such as ≤ <NUM> TAS and ≥ <NUM> TAS, ≤ <NUM> TAS and ≥ <NUM> TAS, or ≤ <NUM> TAS and ≥ <NUM> TAS. Further, DTES can be ≤ <NUM> TAS and ≥ <NUM> TAS, such as ≤ <NUM> TAS and ≥ <NUM> TAS, ≤ <NUM> TAS and ≥ <NUM> TAS, or ≤ <NUM> TAS and ≥ <NUM> TAS. Further still, DTES can be ≤ <NUM> TAS and ≥ <NUM> TAS, such as ≤ <NUM> TAS and ≥ <NUM> TAS, ≤ <NUM> TAS and ≥ <NUM> TAS, or ≤ <NUM> TAS and ≥ <NUM> TAS. Even further, DTES can be ≤ <NUM> TAS and ≥ <NUM> TAS, such as ≤ <NUM> TAS and ≥ <NUM> TAS, ≤ <NUM> TAS and ≥ <NUM> TAS, or ≤ <NUM> TAS and ≥ <NUM> TAS.

The leading edge <NUM> of each serration <NUM> can extend a distance, DLES, into the first grinding face <NUM> or the second grinding face <NUM> and measured perpendicular to the first grinding face <NUM> or the second grinding face <NUM>, and DLES can be ≤ <NUM> TAS, such as ≤ <NUM> TAS, ≤ <NUM> TAS, or ≤ <NUM> TAS. Moreover, DLES can be ≥ <NUM> TAS, such as ≥ <NUM> TAS, ≥ <NUM> TAS, or > <NUM> TAS. In another aspect, DLES can be within a range between and including any of the maximum or minimum values of DLES described herein.

For example, DLES can be ≤ <NUM> TAS and ≥ <NUM> TAS, such as ≤ <NUM> TAS and ≥ <NUM> TAS, ≤ <NUM> TAS and ≥ <NUM> TAS, or ≤ <NUM> TAS and ≥ <NUM> TAS. Further, DLES can be ≤ <NUM> TAS and ≥ <NUM> TAS, such as ≤ <NUM> TAS and ≥ <NUM> TAS, ≤ <NUM> TAS and ≥ <NUM> TAS, or ≤ <NUM> TAS and ≥ <NUM> TAS. Further still, DLES can be ≤ <NUM> TAS and ≥ <NUM> TAS, such as ≤ <NUM> TAS and ≥ <NUM> TAS, ≤ <NUM> TAS and ≥ <NUM> TAS, or ≤ <NUM> TAS and ≥ <NUM> TAS. Even further, DLES can be ≤ <NUM> TAS and ≥ <NUM> TAS, such as ≤ <NUM> TAS and ≥ <NUM> TAS, ≤ <NUM> TAS and ≥ <NUM> TAS, or ≤ <NUM> TAS and ≥ <NUM> TAS.

In another particular aspect, the abrasive segment <NUM> can include a central axis <NUM> that can extend through a center <NUM> of curvature of the abrasive segment and bisect the leading radial sidewall <NUM> of the central segment portion <NUM> of the abrasive segment <NUM>. In this aspect, the first serrated portion <NUM> on the first segment portion <NUM> can lie entirely behind the central axis <NUM> with respect to a direction of rotation of the abrasive segment <NUM>. Further, the second serrated portion <NUM> on the second segment portion <NUM> can lie entirely ahead of the central axis <NUM> with respect to a direction of rotation of the abrasive segment <NUM>.

Further, in a particular aspect, a portion of the inner segment portion <NUM> can extend ahead of the leading radial sidewall <NUM> of the central segment portion <NUM> with respect to the direction of rotation. Moreover, a portion of the outer segment portion <NUM> can extend behind the trailing radial sidewall <NUM> of the central segment portion <NUM> with respect to the direction of rotation.

In a particular aspect, the core <NUM> of the abrasive article <NUM> described herein can be in the form of a cup, a ring, a ring section, a plate, or a disc depending upon the intended application of the abrasive article. The core <NUM> can be made of a metal or metal alloy. For instance, the core <NUM> can be made of steel, and particularly, a heat treatable steel alloys, such as 25CrMo4, 75Cr1, C60, or similar steel alloys for a core having a thin cross section or simple construction steel like St <NUM> or similar for a thick core. The core <NUM> can have a tensile strength of at least about <NUM> N/mm<NUM>. The core <NUM> can be formed by a variety of metallurgical techniques known in the art.

In an exemplary embodiment, the abrasive segments <NUM> can include abrasive particles embedded in a bond matrix. In a particular aspect, the bond matrix can include a metal matrix having a network of interconnected pores. The abrasive particles can include an abrasive material having a Mohs hardness of at least about <NUM>. In particular instances, the abrasive particles can include a superabrasive material, such as diamond or cubic boron nitride. The abrasive particles can have a particle size of not less than about <NUM> mesh, such as not less than about <NUM> mesh, such as between about <NUM> and <NUM> mesh. Depending on the application, the size can be between about <NUM> and <NUM> mesh.

The abrasive particles can be present in an amount between about <NUM> vol% to about <NUM> vol%. Additionally, the amount of abrasive particles may depend on the application. For example, an abrasive segment for a grinding or polishing tool can include between about <NUM> and about <NUM> vol% abrasive particles of the total volume of the abrasive segment. Alternatively, an abrasive segment for a cutting-off tool can include between about <NUM> vol% and about <NUM> vol% abrasive particles of the total volume of the abrasive segment. Further, an abrasive segment for core drilling can include between about <NUM> vol% and about <NUM> vol% abrasive particles of the total volume of the abrasive segment.

The metal matrix can include a metal element or metal alloy including a plurality of metal elements. For certain abrasive segments, the metal matrix can include metal elements such as iron, tungsten, cobalt, nickel, chromium, titanium, silver, and a combination thereof. In particular instances, the metal matrix can include a rare earth element such as cerium, lanthanum, neodymium, and a combination thereof.

In one particular example, the metal matrix can include a wear resistant component. For example, in one embodiment, the metal matrix can include tungsten carbide, and more particularly, may consist essentially of tungsten carbide.

In certain designs, the metal matrix can include particles of individual components or pre-alloyed particles. The particles can be between about <NUM> microns and about <NUM> microns.

In a particular aspect, the abrasive segments <NUM> can be formed such that an infiltrant is present within the interconnected network of pores within the body of the abrasive segment <NUM>. The infiltrant can partially fill, substantially fill, or even completely fill the volume of the pores extending through the volume of the abrasive segment <NUM>. In accordance with one particular design, the infiltrant can be a metal or metal alloy material. For example, some suitable metal elements can include copper, tin, zinc, and a combination thereof.

In particular instances, the infiltrant can be a bronzing material made of a metal alloy, and particular a copper-tin metal alloy, such that it is particularly suited for welding according to embodiments herein. For example, the bronzing material can consist essentially of copper and tin. Certain bronzing materials can incorporate particular contents of tin greater than about <NUM>% by weight, such as greater than about <NUM>% by weight, greater than about <NUM>% by weight, or even greater than about <NUM>% by weight. Further, certain bronzing materials can incorporate particular contents of tin less than about <NUM>% by weight, such as less than about <NUM>% by weight, less than about <NUM>% by weight, or even less than about <NUM>% by weight of the total amount of materials within the composition.

In accordance with an embodiment, the bronzing material can include an amount of tin within a range between and including about <NUM>% by weight and about <NUM>% by weight, such as between and including about <NUM>% by weight and about <NUM>% by weight, between and including about <NUM>% by weight and about <NUM>% by weight, or between and including about <NUM>% by weight and about <NUM>% by weight.

In another embodiment, the bronzing material can include an amount of tin within a range between and including about <NUM>% by weight and about <NUM>% by weight, such as between and including about <NUM>% by weight and about <NUM>% by weight, between and including about <NUM>% by weight and about <NUM>% by weight, or between and including about <NUM>% by weight and about <NUM>% by weight.

Further, in yet another embodiment, the bronzing material can include an amount of tin within a range between and including about <NUM>% by weight and about <NUM>% by weight, such as between and including about <NUM>% by weight and about <NUM>% by weight, between and including about <NUM>% by weight and about <NUM>% by weight, or between and including about <NUM>% by weight and about <NUM>% by weight.

Still further, in accordance with another embodiment, the bronzing material can include an amount of tin within a range between and including about <NUM>% by weight and about <NUM>% by weight, such as between and including about <NUM>% by weight and about <NUM>% by weight, between and including about <NUM>% by weight and about <NUM>% by weight, or between and including about <NUM>% by weight and about <NUM>% by weight.

Moreover, certain bronzing materials can be used as infiltrant material, and can have an amount of copper of at least about <NUM>%, at least about <NUM>%, or even at least about <NUM>% by weight of the total amount of materials within the composition. Some bronzing materials can utilize an amount of copper within a range between about <NUM>% and about <NUM>%, such as between about <NUM>% and about <NUM>%, or even between about <NUM>% and about <NUM>% by weight of the total amount of materials within the composition.

Additionally, the bronzing material may contain a particularly low content of other elements, such as zinc to facilitate proper formation of the abrasive article according to the forming methods of the embodiments herein. For example, the bronzing material may utilize not greater than about <NUM>%, such as not greater than about <NUM>%, or even not greater than about <NUM>% zinc. In fact, certain bronzing materials can be essentially free of zinc.

The abrasive segment <NUM> may be manufactured, such that abrasive particles can be combined with a metal matrix to form a mixture. The metal matrix can include a blend of particles of the components of the metal matrix or can be pre-alloyed particles of the metal matrix. In an embodiment, the metal matrix can conform to the formula (WC)wWxFeyCrzX(<NUM>-w-x-y-z), wherein <NUM>≤w≤<NUM>, <NUM>≤x≤<NUM>, <NUM>≤y≤<NUM>, <NUM>≤z≤<NUM>, w+x+y+z≤<NUM>, and X can include other metals such as cobalt and nickel. In another embodiment, the metal matrix can conform to the formula (WC)wWxFeyCrzAgvX(<NUM>-v-w-x-y-z), wherein <NUM>≤w≤<NUM>, <NUM>≤x≤<NUM>, <NUM>≤y≤<NUM>, <NUM>≤z≤<NUM>, <NUM>≤v≤<NUM>, v+w+x+y+z≤<NUM>, and X can include other metals such as cobalt and nickel.

The mixture of metal matrix and abrasive particles can be formed into an abrasive preform by a pressing operation, particularly a cold pressing operation, to form a porous abrasive segment. The cold pressing can be carried out at a pressure within a range between and including about <NUM> kN/cm<NUM> (<NUM> MPa) to about <NUM> kN/cm<NUM> (<NUM> MPa). The resulting porous abrasive segment can have a network of interconnected pores. In an example, the porous abrasive segment can have a porosity between about <NUM> and <NUM> vol%.

The resulting porous abrasive segment <NUM> can then be subject to an infiltration process, wherein the infiltrant material is disposed within the body of the abrasive segment, and particularly, disposed within the interconnected network of pores within the body of the abrasive segment. The infiltrant may be drawn into the pores of the cold pressed abrasive segment via capillary action. After the infiltration process, the resulting densified abrasive segment can be not less than about <NUM>% dense. The amount of infiltrant that infiltrates the abrasive segment can be between about <NUM> wt% and <NUM> wt% of the densified abrasive segment.

The abrasive segment <NUM> can include a backing region, disposed between the abrasive segment and the base, i.e., the core <NUM>, which facilitates the joining of the abrasive segment and the core <NUM>. According to one embodiment, the backing region can be a distinct region from the abrasive segment <NUM> and the core <NUM>. Still, the backing region can be initially formed as part of the abrasive segment <NUM>, and particularly may be a distinct region of the abrasive segment <NUM> along a bottom surface of the abrasive segment <NUM> that has particular characteristics facilitating the joining of the abrasive segment <NUM> and the core <NUM>. For example, according to one embodiment, the backing region can have a lesser percentage (vol%) of abrasive particles as compared to the amount of abrasive particles within the abrasive segment <NUM>. In fact, in certain instances, the backing region can be essentially free of abrasive particles. This may be particularly suitable for forming methods utilizing a beam of energy (e.g., a laser) used to weld the abrasive segment <NUM> to the core <NUM>.

At least a portion of the backing region can include a bonding composition. The bonding composition can include a metal or metal alloy. Some suitable metal materials can include transition metal elements, including for example, titanium, silver, manganese, phosphorus, aluminum, magnesium, chromium, iron, lead, copper, tin, and a combination thereof.

In particular instances, the bonding composition can be similar to the infiltrant, such that the bonding composition and the infiltrant are different from each other by not greater than a single elemental species. In even more particular instances, the bonding composition can be the same as the infiltrant. According to embodiments herein, the bonding composition can be related to the infiltrant composition in having a certain degree of commonality of elemental species. Quantitatively, an elemental weight percent difference between the bonding composition and the infiltrant composition does not exceed <NUM> weight percent. Elemental weight percent difference is defined as the absolute value of the difference in weight content of each element contained in the bonding composition relative to the infiltrant composition. Other embodiments have closer compositional relationships between the bonding composition and the composition of the infiltrant. The elemental weight percent difference between the bonding composition and the infiltrant composition may, for example, not exceed <NUM> weight percent, <NUM> weight percent, <NUM> weight percent, or may not exceed <NUM> weight percent. An elemental weight percent difference of about zero represents the same composition making up the backing region and the infiltrant. The foregoing elemental values may be measured by any suitable analytical means, including microprobe elemental analysis, and ignores alloying that might take place along areas in which the infiltrant contacts the metal matrix.

The backing region can include at least about <NUM> wt% infiltrant, such as at least about <NUM> wt% infiltrant, such as at least about <NUM> wt% infiltrant. The infiltrant can be continuous throughout the backing region and the densified abrasive segment. In certain instances, the backing region can be formed primarily of the infiltrant material, and in more particular instances, can consist essentially of the infiltrant material. Still, in other embodiments, the backing region can be an infiltrated region, like the abrasive segment. Accordingly, the backing region can include a network of interconnected pores formed between a matrix metal, and wherein the infiltrant material substantially fills the interconnected pores. The backing region can contain similar amounts of matrix metal and infiltrant. Notably, the backing region may be essentially free of abrasive particles. In such embodiments wherein the backing region includes interconnected pores substantially filled with the infiltrant, the infiltrant material can act as a bronzing material in forming a joint (e.g., a welded joint) between the base and the abrasive segment.

In one embodiment, the backing region can be formed of the bronzing material described herein. In fact, certain backing regions can consist essentially of a copper-tin bronzing material having about <NUM>% copper and <NUM>% tin or <NUM>% copper and <NUM>% tin.

In a particular aspect, a method of making the abrasive article <NUM> can include stamping, cutting, drilling, or otherwise forming a core <NUM> having vibration reducing gullets <NUM> and segment support structures <NUM>. The method can include affixing the segments <NUM> to the core <NUM> such that each segment <NUM> is affixed to a segment support structure <NUM>. Affixing the segments <NUM> to the core <NUM> can include welding the abrasive segments <NUM> to the core <NUM>. In particular, the welding process can include impinging a beam of energy at the base of each segment <NUM>. More particularly, in the instance of a segment <NUM> having a backing region, welding can include impinging a beam of energy at the backing region between the abrasive segment <NUM> and the core <NUM>. In particular instances, the beam of energy can be a laser, such that each abrasive segment <NUM> is attached to the core <NUM> via a laser welded bond joint. The laser may be a Roffin laser source commonly available from Dr. Fritsch, GmbH.

In one aspect, each segment <NUM> can be formed by pressing a green segment in a mold and curing the green segment. The pressing can include hot pressing or cold pressing. In another aspect, forming each segment <NUM> can include sintering a green segment, e.g., using an electro-discharge sintering process. In yet another aspect, forming each segment <NUM> can include the infiltration method described herein.

In another aspect, each segment <NUM> can be include a single layer metal bond ("SLMB") segment having a core and a single layer of abrasive electro-plated, or otherwise deposited, on a cutting, or grinding surface of the core.

Claim 1:
An abrasive article (<NUM>), comprising:
a body; and
a plurality of Z-shaped abrasive segments extending from a face of the body,
characterized in that the Z-shaped abrasive segments comprise a segment (<NUM>) including a plurality of outer peripheral serrations (<NUM>) formed in an outer circumferential wall (<NUM>) of the segment.