CA2161031A1 - Knife and method for manufacturing a knife - Google Patents
Knife and method for manufacturing a knifeInfo
- Publication number
- CA2161031A1 CA2161031A1 CA002161031A CA2161031A CA2161031A1 CA 2161031 A1 CA2161031 A1 CA 2161031A1 CA 002161031 A CA002161031 A CA 002161031A CA 2161031 A CA2161031 A CA 2161031A CA 2161031 A1 CA2161031 A1 CA 2161031A1
- Authority
- CA
- Canada
- Prior art keywords
- knife
- coating
- blade
- knife blade
- blade body
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B26—HAND CUTTING TOOLS; CUTTING; SEVERING
- B26B—HAND-HELD CUTTING TOOLS NOT OTHERWISE PROVIDED FOR
- B26B9/00—Blades for hand knives
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23P—METAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS
- B23P15/00—Making specific metal objects by operations not covered by a single other subclass or a group in this subclass
- B23P15/28—Making specific metal objects by operations not covered by a single other subclass or a group in this subclass cutting tools
- B23P15/40—Making specific metal objects by operations not covered by a single other subclass or a group in this subclass cutting tools shearing tools
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B26—HAND CUTTING TOOLS; CUTTING; SEVERING
- B26D—CUTTING; DETAILS COMMON TO MACHINES FOR PERFORATING, PUNCHING, CUTTING-OUT, STAMPING-OUT OR SEVERING
- B26D1/00—Cutting through work characterised by the nature or movement of the cutting member or particular materials not otherwise provided for; Apparatus or machines therefor; Cutting members therefor
- B26D1/0006—Cutting members therefor
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B26—HAND CUTTING TOOLS; CUTTING; SEVERING
- B26D—CUTTING; DETAILS COMMON TO MACHINES FOR PERFORATING, PUNCHING, CUTTING-OUT, STAMPING-OUT OR SEVERING
- B26D1/00—Cutting through work characterised by the nature or movement of the cutting member or particular materials not otherwise provided for; Apparatus or machines therefor; Cutting members therefor
- B26D1/0006—Cutting members therefor
- B26D2001/002—Materials or surface treatments therefor, e.g. composite materials
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B26—HAND CUTTING TOOLS; CUTTING; SEVERING
- B26D—CUTTING; DETAILS COMMON TO MACHINES FOR PERFORATING, PUNCHING, CUTTING-OUT, STAMPING-OUT OR SEVERING
- B26D1/00—Cutting through work characterised by the nature or movement of the cutting member or particular materials not otherwise provided for; Apparatus or machines therefor; Cutting members therefor
- B26D1/0006—Cutting members therefor
- B26D2001/0053—Cutting members therefor having a special cutting edge section or blade section
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- Forests & Forestry (AREA)
- Nonmetal Cutting Devices (AREA)
- Knives (AREA)
- Heat Treatment Of Articles (AREA)
Abstract
The invention relates to a knife, a knife blade or the like, having a blade body (1) consisting of hardened steel, a wide side surface (2) of which forms the substrate for a flame-sprayed hard material coating (3), the second wide side surface (4) of which remains uncoated, and in which the cutting edge is to be formed by an edge (5) of the coating (3) by a ground surface (A) extending from the uncoated side, the ground surface section (6) of the coating connecting with the ground steel surface section (7) of the blade body (1). In order for a self-sharpening effect to occur during cutting for a knife of this kind, the cutting edge connection of the coating to the substrate must be formed microscopically in such a manner that the actual cutting action is not effected by the steel blade body. To this purpose, a connection of the surface section (6) of the coating to the surface section (7) of the blade body (1) is provided in an aligned step-free manner located in the micro region in such a way that the deviation from the line of alignment is less than the peak to valley roughness dimension of the neighbouring ground surface sections (6, 7).
Description
KNIFE AND METHOD FOR MANUFACTURING A KNIFE
The invention relates to a method for manufacturing flame-spray coated knives, knife blades or the like, and a knife, knife blade or the like of this kind according to the preamble of Claim 1 or Claim 17 respectively.
A'knife of this kind and a method for manufacturing such a knife is known from U.S. Patent Specification No. 3,732,771. In this, the blade body, which consists of hard steel, of a knife blade is to be provided on one side with a coating of hard material. In this, there is proposed as coating, inter alia, a flame-sprayed chromium coating.
The coating is to be harder than the material of the steel knife body. The United States patent specification starts from the idea that a knife blade thus coated may have material removed from the uncoated side in such a way that a cutting edge is formed by an edge of the coating. In the normal scale representation in the relevant state of the art, the ground surface section of the coating is to be adjacent to a ground surface section of the steel region. It has been shown in practice that for knife blades, which have been manufactured according to the method there disclosed, the cutting edge formation is not of this kind on the microscopic scale. Seen on the microscopic scale, the ground surface section does not connect in a step-free manner with the ground steel surface section, and in particular does not therefore connect with this section in an aligned manner.
In the case of the method according to German Patent Specification No. 3700250, there is again present at the microscopic level a structure other than that described in the descriptive text.
This differently formed structure, which results from the coating breaking away at the tip during the removal of material from the coating-free wide side surface, has the consequence that the self-sharpening effect desired in the descriptions of the initially-mentioned documents does not occur. The cutting function takes place in the knives described according to the state of the art not at the edge of the coating but at the step in the blade body in the region of the boundary layer between coating and substrate.
It is an object of the invention to overcome this disadvantage of the state of the art by forming the cutting edge connection of the coating to the substrate at the microscopic level in such a manner that the actual cutting operation is not effected by the steel blade body.
This object is met by the knife recited in Claim 1 and by the method recited in Claim 17.
The subsidiary claims represent advantageous further embodiments of the invention.
As a result of the embodiment according to the invention, it is achieved that at the microscopic level also, the boundary surface between the coating and the substrate no longer makes any contribution to the cutting function. It is by contrast brought about that only the cutting edge, which is formed by an edge of the coating, carries out the cutting function. Since in the cutting action, the weaker blade body is subjected to stronger friction than the harder coating and the coating has been applied to the substrate without breaking away, no second cutting edge is formed even with continuous use, which will be formed with steel. It is by contrast achieved that the coating merges in a step-free manner into the steel region, and this microscopic structure remains retained even after quite a long period of time. As a result, there is provided a substantial improvement in the cutting capability compared with a knife according to the state of the art. In cutting tests with standardised abrasive material, it has been shown that knives according to the invention, even after a cutting depth which corresponds to a height of cut material of 23 metres, still have a sharpness which is no longer achieved by comparable ceramic knives even after only some hundreds of millimetres. The self-sharpening effect claimed in the state of the art as an objective actually occurs for knives according to the invention. Compared with customary coated steel knives, the improvement in cutting capability is more evident. While conventional coated steel knives were already blunt after a cutting depth of 130 mm during tests, for knives according to the invention, the flattening of the coating at the cutting edge had stabilised in the region of 1 to 3 um. The knife remained sharp to the same extent. In a preferred embodiment of a knife according to the invention, in which the ground surface section of the coating, which connects in a step-free manner with the ground steel surface section of the blade body, has a lower peak to valley roughness dimension than the wide side surface of the coating, a further improved cutting capability is achieved. It may further be provided that the peak to valley roughness dimension of the ground surface section is substantially identical to the peak to valley roughness dimension of the ground surface section of the steel knife body. The peak to valley roughness dimension of the wide side surface of the coating may amount to approximately 10 um or less. The peak to valley roughness dimension of the ground surface section may amount to approximately 5 um or less. It has been shown that in the flame-spray coating, the steel knife body is heated up. This temperature elevation in the region of the coated surface leads to a tempering and a reduction in hardness in the region of the boundary layer. In the state of the art, the tempered zone has a very great thickness, so that the retention of the coating on the knife body is not optimal, with the result noted initially, that the coating breaks away. It is now provided according to the invention that the tempered zone has a minimised thickness. The thickness of the tempered zone should to this end preferably be less than the thickness of the coating and preferably less than 5 or 10 um. As a result of this embodiment, the core of the knife body is not influenced by the flame-spraying in respect of its hardness. Only in a very thin zone in the region of the boundary surface, which preferably is formed to be so thin that it is no longer apparent, is the knife body tempered and has a reduced hardness. The thickness of the coating is preferably between 10 and 60 um, depending on the material used for the coating. It has been found that an optimal coating thickness amounts to approximately 30 to 40 um. By this thickness of coating, there is on the one hand formed a sufficiently larger grindable surface region of the coating and on the other hand, the coating is sufficiently thin as not to break away. It may be further provided that the thickness of the tempered zone extends in a homogeneous manner over the entire coated wide side surface, having therefore substantially a uniform thickness. The coating may consist of a hard carrier material, in which particles of hard material are embedded. The thickness of the tempered zone should be at a maximum ten times as great as the thickness of the particles of hard material. By selection of these sizes, it is assured that in the coating, the particles of hard material burying themselves in the surface enter into an optimal retention with the weaker knife body zone. The particles of hard material may consist of tungsten carbide and the carrier material may consist of cobalt. The particles of hard material and the carrier material may be formulated in a ratio of 80:20 to 90:10. A ratio of 88:12 is preferred. In an embodiment which is not at present preferred, there may be provided, in addition to a first component consisting of tungsten carbide/cobalt, a second component for the coating which has in particular, nickel, chromium, boron and/or silicon. The second component should then amount to less than 50%, preferably 30%, of the coating composition. The hardness of the coating is preferably far above the hardness of the blade body. For a coating with tungsten carbide grains, according to the literature, a hardness of 1800 HV 0.3 is prescribed. This hardness is to be compared with a hardness for the knife body of approximately 650 HV
0.3. The hardness of the tempered zone is less than the hardness of the blade body and may amount to approximately 550 HV 0.3.
The method according to the invention for manufacturing a knife blade provides that a coating of hard material is flame-sprayed on at high speed on one side of the hardened basic blade body, and that subsequently the blade is ground on the other side. To this end, it is provided that the surface region to be coated is bombarded with an abrasive granulate before the coating with hard material. In this manner, the peak to valley roughness dimension of the surface to be coated is to be changed. The bombardment with the granulate is to be effected in such a manner that the tip region of the blade body is bent sideways as a result of the bombardment pressure. In section through a bombarded blade body, a nose which is bent sideways is then formed at the cutting edge. This nose is also sprayed in the subsequent flame-spray coating and is then ground away. Preferably the coating with hard material is carried out at supersonic speed. The powder-form coating material entrained in the flame is to be heated up in the flame to approximately 2000 to 3000C. In order to avoid that the wide side surface of the blade body is heated up to an impermissible level during the flame-spray coating, it is provided that the blade is coated in several successive steps, each consisting of a thin partial coating. The surface has therefore the opportunity to cool down again between the application of the individual partial layers. In addition, less heat requires to be conducted away on account of the lesser amount of material applied in each case in the individual partial steps. ~uring the coating, the surface of the blade body should preferably be heated up for a short period only to 400C at a maximum. The opposite side should thereby reach 80 at a maximum. Only in the region of the tip zone, which is later ground ~ 2161031 away, is a higher temperature permissible. In this process, the weaker tempered zone is reduced to a minimum which is no longer detectable. The grinding of the blade should preferably be carried out in several successive steps. There is preferably achieved in the first grinding step, the removal of the tip zone already mentioned.
In this, there must be accepted a breaking away of the coating in this region. In one or several second material removal steps, the blade body and the coating may then be ground to such an extent that the ground surface regions of blade body and coating x are aligned with one another. The heat impact during the high speed flame-spraying is so selected in combination with the impact time that no localised corrosion or pitting occurs either at the cutting edge or on the wide side surface in use of the finished knife. The coating parameters are preferably so selected that the thermal loading on the blade body does not lead to any damaging stresses in the blade body.
An embodiment of the invention is described below having regard to the accompanying drawings.
Figure 1 shows a knife according to the invention in front view, Figure 2 is a section on the line II-II of Figure 1, Figure 3 shows the microscopic representation of the cutting edge region of a knife manufactured by a process according to the state of the art, Figure 4 shows the microscopic representation of the cutting edge region of a non-bombarded/non-coated blade body in the region of the cutting edge, Figure 5 is a representation according to Figure 4 after the bombardment, Figure 6 is a representation following on Figure 5 and in accordance with Figure 5, following the coating, Figure 7 is a representation following on Figure 6, after the first removal of material, Figure 8 is an enlarged representation following on Figure 7, after the final removal of material, Figure 9 is an enlarged representation of the cutting edge region of a knife according to the invention, Figure 10 is an enlarged representation of the coated intermediate product before the first removal of material, and Figure 11 is a schematic representation of the progression of the hardness along the line XI-XI in Figure 9.
The starting point of the invention is shown in Figure 3.
There is there in question a section through the cutting edge region of a blade, which has been coated according to the state of the art initially identified. There is formed in the case of this knife an edge (projection U), which is defined by two surfaces of the coating, but this edge is not the cutting edge. The cutting edge is formed by the steel backing material 1 and moreover by a projection bordered by the broad side surface 2 to be coated. In the microscopic representation shown in Figure 3, it is apparent that the retention of the coating 3 on the boundary layer 2 is only insufficient. In the cutting process, the end face of the coating is not abraded away.
There break away rather fragments of the coating from the boundary layer 2, so that in the cutting region, the coating has no significance.
The knife according to the invention has a blade body 1, which consists of hardened steel. According to Figure 4, the blank to be coated is ground to a cutting edge. By this there results a sharpened tip region 11 for a cutting edge, which separates the two opposed wide side surfaces 2 and 4. The two wide side surfaces 2 and 4 meet one another in the tip region 11 at a sharp angle.
After manufacture of the blank according to Figure 4, the blank is bombarded with granulate in the cutting edge region of one wide side surface 2. The particles of granulate are fine-grained and abrasive. The wide side surface 2 is roughened by this bombardment.
The bombardment is effected with an intensity and for a duration such that the tip region 11 is bent around in the direction turned away from the steel. In sectionr there results thereby a nose-shaped bent portion ~see Figure 5).
In a subsequent process step, the bombarded wide side surface 2 is provided with a coating of hard material. The hard material consists of tungsten carbide particles of approximately 1 um diameter. The tungsten carbide particles are embedded in a cobalt matrix. The coating is effected by the flame spray process. To this end, the coating material is put in powder form into a flame and heated up to approximately 2000 to 3000C by means of the flame. The mass thus heated up is then applied at very high speed, in fact at a supersonic speed, onto the substrate formed by the wide side surface 2 of the blade body 1.
A very thin first layer is initially applied, in which the particles of hard material are also embedded into the treated surface of the wide side surface 2 and are anchored therein. The thin coat application results therefore in the spray coating with corresponding speed the wide side surface 2. The speed and the spray intensity are selected so that the surface of the wide side surface is heated up to at most 400C during this coating, to a temperature therefore at which no damaging softening of the material takes place. In further coating steps, a multiplicity of thin layers are successively applied, until the required thickness of the coating 3 is achieved.
The coating material consists of a mixture of tungsten carbide particles and cobalt in a mixture ratio of 88 to 12. The coating then also consists of exactly this ratio. The coating 3 extends over the cutting edge end section of the wide side surface 2 up to over the central plane of the cutting edge region of the blade body and beyond it in a direction towards the uncoated wide side surface, since the tip region 11 is bent in the direction of the lee side. It is permissible for the tip region 11 to be heated up during the coating to a higher temperature than the remainder of the wide side surface 2 to be coated. The temperature to which the tip region 11 is heated may therefore be so great that the entire tip region experiences a softening of the material.
In the method step illustrated in Figure 7, the cutting edge is in a first material removal step ground from the uncoated side 4.
The removal of material is achieved by a grindstone, which is rotated. In the method step shown in Figure 7, the entire tip region 11 is taken away. In this, it must be accepted that a partial region of the coating 2 is broken off at the boundary surface between coating and substrate. By this, a projection 12 is formed. This projection 12 is taken away again in subsequent material removal steps (see Figure 8) until the ground surface A consists of two surface sections 6 and 7 which are aligned with one another, the surface section 6 being associated with the layer 3 and surface section 7 with the steel blade body 1. During the removal of material, the ground surface is made smooth, so that the surface section 6 has a smaller peak to valley roughness dimension than the surface section 8, which is provided by the flame coating. The cutting edge is formed by the edge 5. The surface sections 6 and 8 thus meet one another at an angle of preferably 22 to 24. In Figure 9, the actual structure achieved for the cutting edge section is shown. The surface sections 6 and 7 merge into one another in a step-free manner and have the same roughness (peak to valley height), which is less than the peak to valley height of the surface 8. The thickness D amounts in the embodiment to less than 1 um and is therefore shown in the drawings to a disproportionately large scale. The thickness S of the layer of hard material amounts to 30 um.
The ground surface A results in a sharp angle (22 to 24) towards the uncoated wide side, so that a cutting edge 5 is formed with a less acute angle than the tip angle of the tip 11 of the blank (Figure 4). The length of the steel section removed is about four times longer than the length of the section 6. In the case of a typical coating thickness of approximately 30 um, there thus results a ground surface A in which the coating sections 6 and 7 merge microscopically in aligned manner into one another, so that it is assured that the cutting edge is formed by the edge 5 of the coating.
Depending on the hardness of the coating material, the selection of the coating thickness is effected so that this is not broken off by correct use of the knife. The thickness of the starting zone has importance as a further parameter; its thickness is chosen so that an optimal anchoring of the coating is achieved by the tungsten carbide particles entering into the surface 2 of the steel body.
The run or variation of the hardness in the cutting edge section is shown in Figure 11. The coating 3 has throughout its thickness S a substantially constant hardness, namely approximately 1800 HV 0.3. In the region of the boundary surface, the hardness reduces abruptly to a value which amounts to approximately 550 HV
0.3. This value is associated with the tempered zone 9. Across the thickness D of the tempered zone 9, the hardness increases continuously with greater depth T up to the hardness of the bulk material of the blade body 1. Here the hardness is 650 HV 0.3.
As may be seen from Figure 10, the thickness of the tempered zone 9 is constantly thick over the entire extent of the cross-section of the layer 3. In Figure 10, the thickness is shown to an enlarged scale. In ideal conditions, it is substantially less than 1 um, not therefore to-be checked by etching or the like. The end of the boundary layer 9 is represented by the broken line. In the region of ` 2l6Io3l the tip zone 11, a greater thickness of the tempered zone 9 is permissible. In the exemplary embodiment, the entire tip 11 is associated with the tempered zone 9. It is however provided that this section, in which the tempered zone is thicker than in the remainder of S the coated section, is subsequently taken away. In the region 14 of the layer 3 remote from the cutting edge, the layer continuously tapers off. The boundary (broken line) of the tempered zone 9 here runs into the wide side surface, so that a tempered outer surface region 13 results, the extent of which corresponds to the thickness D of the tempered zone 9.
All features disclosed are inventive. In the publication of the application, there is in this regard also to be taken into account as to their complete content, the disclosure content of the associated/accompanying priority documents (copy of the earlier application), also to this end, features of these documents are to be incorporated in the claims of the present application.
The invention relates to a method for manufacturing flame-spray coated knives, knife blades or the like, and a knife, knife blade or the like of this kind according to the preamble of Claim 1 or Claim 17 respectively.
A'knife of this kind and a method for manufacturing such a knife is known from U.S. Patent Specification No. 3,732,771. In this, the blade body, which consists of hard steel, of a knife blade is to be provided on one side with a coating of hard material. In this, there is proposed as coating, inter alia, a flame-sprayed chromium coating.
The coating is to be harder than the material of the steel knife body. The United States patent specification starts from the idea that a knife blade thus coated may have material removed from the uncoated side in such a way that a cutting edge is formed by an edge of the coating. In the normal scale representation in the relevant state of the art, the ground surface section of the coating is to be adjacent to a ground surface section of the steel region. It has been shown in practice that for knife blades, which have been manufactured according to the method there disclosed, the cutting edge formation is not of this kind on the microscopic scale. Seen on the microscopic scale, the ground surface section does not connect in a step-free manner with the ground steel surface section, and in particular does not therefore connect with this section in an aligned manner.
In the case of the method according to German Patent Specification No. 3700250, there is again present at the microscopic level a structure other than that described in the descriptive text.
This differently formed structure, which results from the coating breaking away at the tip during the removal of material from the coating-free wide side surface, has the consequence that the self-sharpening effect desired in the descriptions of the initially-mentioned documents does not occur. The cutting function takes place in the knives described according to the state of the art not at the edge of the coating but at the step in the blade body in the region of the boundary layer between coating and substrate.
It is an object of the invention to overcome this disadvantage of the state of the art by forming the cutting edge connection of the coating to the substrate at the microscopic level in such a manner that the actual cutting operation is not effected by the steel blade body.
This object is met by the knife recited in Claim 1 and by the method recited in Claim 17.
The subsidiary claims represent advantageous further embodiments of the invention.
As a result of the embodiment according to the invention, it is achieved that at the microscopic level also, the boundary surface between the coating and the substrate no longer makes any contribution to the cutting function. It is by contrast brought about that only the cutting edge, which is formed by an edge of the coating, carries out the cutting function. Since in the cutting action, the weaker blade body is subjected to stronger friction than the harder coating and the coating has been applied to the substrate without breaking away, no second cutting edge is formed even with continuous use, which will be formed with steel. It is by contrast achieved that the coating merges in a step-free manner into the steel region, and this microscopic structure remains retained even after quite a long period of time. As a result, there is provided a substantial improvement in the cutting capability compared with a knife according to the state of the art. In cutting tests with standardised abrasive material, it has been shown that knives according to the invention, even after a cutting depth which corresponds to a height of cut material of 23 metres, still have a sharpness which is no longer achieved by comparable ceramic knives even after only some hundreds of millimetres. The self-sharpening effect claimed in the state of the art as an objective actually occurs for knives according to the invention. Compared with customary coated steel knives, the improvement in cutting capability is more evident. While conventional coated steel knives were already blunt after a cutting depth of 130 mm during tests, for knives according to the invention, the flattening of the coating at the cutting edge had stabilised in the region of 1 to 3 um. The knife remained sharp to the same extent. In a preferred embodiment of a knife according to the invention, in which the ground surface section of the coating, which connects in a step-free manner with the ground steel surface section of the blade body, has a lower peak to valley roughness dimension than the wide side surface of the coating, a further improved cutting capability is achieved. It may further be provided that the peak to valley roughness dimension of the ground surface section is substantially identical to the peak to valley roughness dimension of the ground surface section of the steel knife body. The peak to valley roughness dimension of the wide side surface of the coating may amount to approximately 10 um or less. The peak to valley roughness dimension of the ground surface section may amount to approximately 5 um or less. It has been shown that in the flame-spray coating, the steel knife body is heated up. This temperature elevation in the region of the coated surface leads to a tempering and a reduction in hardness in the region of the boundary layer. In the state of the art, the tempered zone has a very great thickness, so that the retention of the coating on the knife body is not optimal, with the result noted initially, that the coating breaks away. It is now provided according to the invention that the tempered zone has a minimised thickness. The thickness of the tempered zone should to this end preferably be less than the thickness of the coating and preferably less than 5 or 10 um. As a result of this embodiment, the core of the knife body is not influenced by the flame-spraying in respect of its hardness. Only in a very thin zone in the region of the boundary surface, which preferably is formed to be so thin that it is no longer apparent, is the knife body tempered and has a reduced hardness. The thickness of the coating is preferably between 10 and 60 um, depending on the material used for the coating. It has been found that an optimal coating thickness amounts to approximately 30 to 40 um. By this thickness of coating, there is on the one hand formed a sufficiently larger grindable surface region of the coating and on the other hand, the coating is sufficiently thin as not to break away. It may be further provided that the thickness of the tempered zone extends in a homogeneous manner over the entire coated wide side surface, having therefore substantially a uniform thickness. The coating may consist of a hard carrier material, in which particles of hard material are embedded. The thickness of the tempered zone should be at a maximum ten times as great as the thickness of the particles of hard material. By selection of these sizes, it is assured that in the coating, the particles of hard material burying themselves in the surface enter into an optimal retention with the weaker knife body zone. The particles of hard material may consist of tungsten carbide and the carrier material may consist of cobalt. The particles of hard material and the carrier material may be formulated in a ratio of 80:20 to 90:10. A ratio of 88:12 is preferred. In an embodiment which is not at present preferred, there may be provided, in addition to a first component consisting of tungsten carbide/cobalt, a second component for the coating which has in particular, nickel, chromium, boron and/or silicon. The second component should then amount to less than 50%, preferably 30%, of the coating composition. The hardness of the coating is preferably far above the hardness of the blade body. For a coating with tungsten carbide grains, according to the literature, a hardness of 1800 HV 0.3 is prescribed. This hardness is to be compared with a hardness for the knife body of approximately 650 HV
0.3. The hardness of the tempered zone is less than the hardness of the blade body and may amount to approximately 550 HV 0.3.
The method according to the invention for manufacturing a knife blade provides that a coating of hard material is flame-sprayed on at high speed on one side of the hardened basic blade body, and that subsequently the blade is ground on the other side. To this end, it is provided that the surface region to be coated is bombarded with an abrasive granulate before the coating with hard material. In this manner, the peak to valley roughness dimension of the surface to be coated is to be changed. The bombardment with the granulate is to be effected in such a manner that the tip region of the blade body is bent sideways as a result of the bombardment pressure. In section through a bombarded blade body, a nose which is bent sideways is then formed at the cutting edge. This nose is also sprayed in the subsequent flame-spray coating and is then ground away. Preferably the coating with hard material is carried out at supersonic speed. The powder-form coating material entrained in the flame is to be heated up in the flame to approximately 2000 to 3000C. In order to avoid that the wide side surface of the blade body is heated up to an impermissible level during the flame-spray coating, it is provided that the blade is coated in several successive steps, each consisting of a thin partial coating. The surface has therefore the opportunity to cool down again between the application of the individual partial layers. In addition, less heat requires to be conducted away on account of the lesser amount of material applied in each case in the individual partial steps. ~uring the coating, the surface of the blade body should preferably be heated up for a short period only to 400C at a maximum. The opposite side should thereby reach 80 at a maximum. Only in the region of the tip zone, which is later ground ~ 2161031 away, is a higher temperature permissible. In this process, the weaker tempered zone is reduced to a minimum which is no longer detectable. The grinding of the blade should preferably be carried out in several successive steps. There is preferably achieved in the first grinding step, the removal of the tip zone already mentioned.
In this, there must be accepted a breaking away of the coating in this region. In one or several second material removal steps, the blade body and the coating may then be ground to such an extent that the ground surface regions of blade body and coating x are aligned with one another. The heat impact during the high speed flame-spraying is so selected in combination with the impact time that no localised corrosion or pitting occurs either at the cutting edge or on the wide side surface in use of the finished knife. The coating parameters are preferably so selected that the thermal loading on the blade body does not lead to any damaging stresses in the blade body.
An embodiment of the invention is described below having regard to the accompanying drawings.
Figure 1 shows a knife according to the invention in front view, Figure 2 is a section on the line II-II of Figure 1, Figure 3 shows the microscopic representation of the cutting edge region of a knife manufactured by a process according to the state of the art, Figure 4 shows the microscopic representation of the cutting edge region of a non-bombarded/non-coated blade body in the region of the cutting edge, Figure 5 is a representation according to Figure 4 after the bombardment, Figure 6 is a representation following on Figure 5 and in accordance with Figure 5, following the coating, Figure 7 is a representation following on Figure 6, after the first removal of material, Figure 8 is an enlarged representation following on Figure 7, after the final removal of material, Figure 9 is an enlarged representation of the cutting edge region of a knife according to the invention, Figure 10 is an enlarged representation of the coated intermediate product before the first removal of material, and Figure 11 is a schematic representation of the progression of the hardness along the line XI-XI in Figure 9.
The starting point of the invention is shown in Figure 3.
There is there in question a section through the cutting edge region of a blade, which has been coated according to the state of the art initially identified. There is formed in the case of this knife an edge (projection U), which is defined by two surfaces of the coating, but this edge is not the cutting edge. The cutting edge is formed by the steel backing material 1 and moreover by a projection bordered by the broad side surface 2 to be coated. In the microscopic representation shown in Figure 3, it is apparent that the retention of the coating 3 on the boundary layer 2 is only insufficient. In the cutting process, the end face of the coating is not abraded away.
There break away rather fragments of the coating from the boundary layer 2, so that in the cutting region, the coating has no significance.
The knife according to the invention has a blade body 1, which consists of hardened steel. According to Figure 4, the blank to be coated is ground to a cutting edge. By this there results a sharpened tip region 11 for a cutting edge, which separates the two opposed wide side surfaces 2 and 4. The two wide side surfaces 2 and 4 meet one another in the tip region 11 at a sharp angle.
After manufacture of the blank according to Figure 4, the blank is bombarded with granulate in the cutting edge region of one wide side surface 2. The particles of granulate are fine-grained and abrasive. The wide side surface 2 is roughened by this bombardment.
The bombardment is effected with an intensity and for a duration such that the tip region 11 is bent around in the direction turned away from the steel. In sectionr there results thereby a nose-shaped bent portion ~see Figure 5).
In a subsequent process step, the bombarded wide side surface 2 is provided with a coating of hard material. The hard material consists of tungsten carbide particles of approximately 1 um diameter. The tungsten carbide particles are embedded in a cobalt matrix. The coating is effected by the flame spray process. To this end, the coating material is put in powder form into a flame and heated up to approximately 2000 to 3000C by means of the flame. The mass thus heated up is then applied at very high speed, in fact at a supersonic speed, onto the substrate formed by the wide side surface 2 of the blade body 1.
A very thin first layer is initially applied, in which the particles of hard material are also embedded into the treated surface of the wide side surface 2 and are anchored therein. The thin coat application results therefore in the spray coating with corresponding speed the wide side surface 2. The speed and the spray intensity are selected so that the surface of the wide side surface is heated up to at most 400C during this coating, to a temperature therefore at which no damaging softening of the material takes place. In further coating steps, a multiplicity of thin layers are successively applied, until the required thickness of the coating 3 is achieved.
The coating material consists of a mixture of tungsten carbide particles and cobalt in a mixture ratio of 88 to 12. The coating then also consists of exactly this ratio. The coating 3 extends over the cutting edge end section of the wide side surface 2 up to over the central plane of the cutting edge region of the blade body and beyond it in a direction towards the uncoated wide side surface, since the tip region 11 is bent in the direction of the lee side. It is permissible for the tip region 11 to be heated up during the coating to a higher temperature than the remainder of the wide side surface 2 to be coated. The temperature to which the tip region 11 is heated may therefore be so great that the entire tip region experiences a softening of the material.
In the method step illustrated in Figure 7, the cutting edge is in a first material removal step ground from the uncoated side 4.
The removal of material is achieved by a grindstone, which is rotated. In the method step shown in Figure 7, the entire tip region 11 is taken away. In this, it must be accepted that a partial region of the coating 2 is broken off at the boundary surface between coating and substrate. By this, a projection 12 is formed. This projection 12 is taken away again in subsequent material removal steps (see Figure 8) until the ground surface A consists of two surface sections 6 and 7 which are aligned with one another, the surface section 6 being associated with the layer 3 and surface section 7 with the steel blade body 1. During the removal of material, the ground surface is made smooth, so that the surface section 6 has a smaller peak to valley roughness dimension than the surface section 8, which is provided by the flame coating. The cutting edge is formed by the edge 5. The surface sections 6 and 8 thus meet one another at an angle of preferably 22 to 24. In Figure 9, the actual structure achieved for the cutting edge section is shown. The surface sections 6 and 7 merge into one another in a step-free manner and have the same roughness (peak to valley height), which is less than the peak to valley height of the surface 8. The thickness D amounts in the embodiment to less than 1 um and is therefore shown in the drawings to a disproportionately large scale. The thickness S of the layer of hard material amounts to 30 um.
The ground surface A results in a sharp angle (22 to 24) towards the uncoated wide side, so that a cutting edge 5 is formed with a less acute angle than the tip angle of the tip 11 of the blank (Figure 4). The length of the steel section removed is about four times longer than the length of the section 6. In the case of a typical coating thickness of approximately 30 um, there thus results a ground surface A in which the coating sections 6 and 7 merge microscopically in aligned manner into one another, so that it is assured that the cutting edge is formed by the edge 5 of the coating.
Depending on the hardness of the coating material, the selection of the coating thickness is effected so that this is not broken off by correct use of the knife. The thickness of the starting zone has importance as a further parameter; its thickness is chosen so that an optimal anchoring of the coating is achieved by the tungsten carbide particles entering into the surface 2 of the steel body.
The run or variation of the hardness in the cutting edge section is shown in Figure 11. The coating 3 has throughout its thickness S a substantially constant hardness, namely approximately 1800 HV 0.3. In the region of the boundary surface, the hardness reduces abruptly to a value which amounts to approximately 550 HV
0.3. This value is associated with the tempered zone 9. Across the thickness D of the tempered zone 9, the hardness increases continuously with greater depth T up to the hardness of the bulk material of the blade body 1. Here the hardness is 650 HV 0.3.
As may be seen from Figure 10, the thickness of the tempered zone 9 is constantly thick over the entire extent of the cross-section of the layer 3. In Figure 10, the thickness is shown to an enlarged scale. In ideal conditions, it is substantially less than 1 um, not therefore to-be checked by etching or the like. The end of the boundary layer 9 is represented by the broken line. In the region of ` 2l6Io3l the tip zone 11, a greater thickness of the tempered zone 9 is permissible. In the exemplary embodiment, the entire tip 11 is associated with the tempered zone 9. It is however provided that this section, in which the tempered zone is thicker than in the remainder of S the coated section, is subsequently taken away. In the region 14 of the layer 3 remote from the cutting edge, the layer continuously tapers off. The boundary (broken line) of the tempered zone 9 here runs into the wide side surface, so that a tempered outer surface region 13 results, the extent of which corresponds to the thickness D of the tempered zone 9.
All features disclosed are inventive. In the publication of the application, there is in this regard also to be taken into account as to their complete content, the disclosure content of the associated/accompanying priority documents (copy of the earlier application), also to this end, features of these documents are to be incorporated in the claims of the present application.
Claims (24)
1. Knife, knife blade or the like, having a blade body (1) consisting of hardened steel, a wide side surface (2) of which forms the substrate for a flame sprayed coating (3) of hard material, the second wide side surface (4) of which remains uncoated, and in which the cutting edge is to be formed by an edge (5) of the coating by a ground surface (A) extending from the uncoated side, the ground surface section (6) of the coating adjoining the ground steel surface section (7) of the blade body (1), characterised by a connection, located in the microregion, of the surface section (6) of the coating in an aligned step-free manner to the surface section (7) of the blade body (1) in such a manner that the deviation from the line of alignment is less than the peak to valley dimension (roughness) of the neighbouring ground surface sections (6, 7).
2. Knife, knife blade or the like according to Claim 1 characterised in that the ground surface section (6) of the coating (3), which connects in step-free manner with the ground steel surface section (7) of the blade body (1), has a smaller peak to valley height (roughness) than the wide side surface (8) of the coating 3.
3. Knife, knife blade or the like according to one or more of the preceding claims, characterised in that the ground surface section (6) of the coating (3), which connects in a step-free manner with the ground steel surface section (7) of the blade body (1), has a peak to valley height (roughness) which is substantially the same as the peak to valley height of the ground steel section (7) of the coating (3).
4. Knife, knife blade or the like according to one or more of the preceding claims, characterised in that the peak to valley height of the wide side surface (8) of the coating (3) is approximately 10 um or less and the peak to valley height of the ground surface section (6) of the coating is approximately 5 um or less.
5. Knife, knife blade or the like according to one or more of the preceding claims, characterised by a coating resulting from a minimisation of the thickness (D) of a tempered zone (9), which has a lower hardness than the steel blade body (1), the coating not breaking away on removal of material from the uncoated wide side surface (4).
6. Knife, knife blade or the like according to one or more of the preceding claims, characterised in that the coating thickness (D) of the tempered zone (9) is less than the thickness (S) of the coating (3) and preferably less than 10 um or 5 um.
7. Knife, knife blade or the like according to one or more of the preceding claims, characterised in that the thickness (S) of the coating is between 10 and 60 um, preferably approximately 40 um.
8. Knife, knife blade or the like according to one or more of the preceding claims, characterised in that the thickness (D) of the tempered zone (9) has a substantially uniform thickness over the entire coated wide side surface (2).
9. Knife, knife blade or the like according to one or more of the preceding claims, characterised in that the coating (3) consists of a hard carrier material, in which particles (10) of hard material are embedded.
10. Knife, knife blade or the like according to one or more of the preceding claims, characterised in that the thickness (D) of the starting zone (9) is a maximum of ten times as large as the thickness of the particles (10) of hard material.
11. Knife, knife blade or the like according to one or more of the preceding claims, characterised in that the particles (10) of hard material consist of tungsten carbide and the carrier material is cobalt.
12. Knife, knife blade or the like according to one or more of the preceding claims, characterised in that the particles of hard material and the carrier material are applied in a ratio of 80 to 20 to 90 to 10, preferably 88 to 12.
13. Knife, knife blade or the like according to one or more of the preceding claims, characterised in that the coating, in addition to a first component consisting of tungsten carbide/cobalt, has a second component of in particular nickel, chromium, boron and/or silicon.
14. Knife, knife blade or the like according to one or more of the preceding claims, characterised in that the second component makes up less than 50%, preferably 30%, of the coating composition.
15. Knife, knife blade or the like according to one or more of the preceding claims, characterised in that the hardness of the coating (3) is preferably approximately 1800 HV 0.3 and is harder than the hardness of the blade body (1), which preferably has a hardness of 650 HV 0.3, which in turn is harder than the hardness of the tempered zone (9), which is preferably approximately 550 HV 0.3.
16. Method for manufacturing a knife blade or the like, a coating (2) of hard material being sprayed onto the hardened blade body on the one hand and subsequently on the other hand the blade being ground, characterised in that the surface region (2) to be coated is bombarded with an abrasive granulate before the coating with hard material, and that the tip region (11) of the blade body is weakened at the sides as a result of the bombardment pressure.
17. Method for manufacturing a knife blade or the like, in particular according to Claim 16, characterised in that the flame coating with hard material is effected at supersonic velocity.
18. Knife, knife blade or the like and a method for manufacturing a knife blade or the like, in particular according to one or more of of the preceding claims, characterised in that the hard material flame coating is effected at a temperature of 2000°C to 3000°C.
19. Knife, knife blade or the like and a method for manufacturing a knife blade or the like, in particular according to one or more of the preceding claims, characterised in that in coating the coated side surface (2) of the blade body (1), a temperature of at most 400°C is reached for a short period, a higher temperature being permissible in the region of the tip zone (11).
20. Knife, knife blade or the like and a method for manufacturing a knife blade or the like, in particular according to one or more of the preceding claims, characterised in that the blade is ground in several successive steps.
21. Knife, knife blade or the like and a method for manufacturing a knife blade or the like, in particular according to one or more of the preceding claims, characterised in that the coating with hard material is effected in the form of a multiplicity of successively applied thin part coatings.
22. Knife, knife blade or the like and a method for manufacturing a knife blade or the like, in particular according to one or more of the preceding claims, characterised in that in a first material removal step, the laterally weakened tip zone (11) is removed with acceptance of a thus resulting breaking away of the coating.
23. Knife, knife blade or the like and a method for manufacturing a knife blade or the like, in particular according to one or more of the preceding claims, characterised in that in one or several second material removal steps, so much material is removed from the coating (3) and from the blade body (1) that the two ground surface sections (6) and (7) are aligned with one another.
24. Intermediate product for a knife, knife blade or the like having a blade body (1) consisting of hardened steel, a wide side surface (2) of which forms the substrate for a flame-sprayed hard material coating (3), a second side surface (4) of which remains uncoated, and in which the cutting edge is to be formed by an edge (5) of the coating (3) by a ground surface (A) extending from the uncoated side, characterised by d laterally turned-aside tip zone (11) of the blade body (1), which is turned aside in the opposite direction to the coating (3), and which is coated up to the centre line of the blade tip.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE4437911A DE4437911A1 (en) | 1994-10-22 | 1994-10-22 | Knife and method of making a knife |
| DEP4437911.0 | 1994-10-22 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2161031A1 true CA2161031A1 (en) | 1996-04-23 |
Family
ID=6531527
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002161031A Abandoned CA2161031A1 (en) | 1994-10-22 | 1995-10-20 | Knife and method for manufacturing a knife |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP0707921B1 (en) |
| JP (1) | JPH08206989A (en) |
| KR (1) | KR960013588A (en) |
| BR (1) | BR9504506A (en) |
| CA (1) | CA2161031A1 (en) |
| DE (2) | DE4437911A1 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6422110B1 (en) | 1999-08-12 | 2002-07-23 | C & E. Fein Gmbh & Co. | Cutting knife for severing tough elastic materials and production method therefor |
| EP2527492A1 (en) * | 2010-01-20 | 2012-11-28 | IHI Corporation | Cutting edge structure for cutting tool, and cutting tool with the cutting edge structure |
| US8505414B2 (en) | 2008-06-23 | 2013-08-13 | Stanley Black & Decker, Inc. | Method of manufacturing a blade |
| US8769833B2 (en) | 2010-09-10 | 2014-07-08 | Stanley Black & Decker, Inc. | Utility knife blade |
Families Citing this family (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE29710489U1 (en) * | 1997-06-17 | 1998-10-15 | P.D. Rasspe Söhne GmbH & Co KG, 42651 Solingen | Round knife |
| DE19902818C2 (en) * | 1999-01-25 | 2003-03-27 | Wolfgang Bauer | Metal knife with specially adapted material hardness distribution for shredding and cutting machines |
| GB0207375D0 (en) | 2002-03-28 | 2002-05-08 | Hardide Ltd | Cutting tool with hard coating |
| US7194933B2 (en) * | 2002-07-01 | 2007-03-27 | Premark Feg L.L.C. | Composite circular slicer knife |
| KR100573371B1 (en) * | 2003-07-21 | 2006-04-25 | 김원철 | The site other opinion picket spatial-temporal method which applies the meritorious metal tubing |
| FR2868725B1 (en) * | 2004-04-08 | 2006-06-02 | Tarreirias Bonjean Sa Soc D Ex | PROCESS FOR PRODUCING A CUTTING BLADE |
| BRPI0507300B1 (en) | 2004-02-18 | 2019-11-26 | Soc D Exploitation Tarrerias Bonjean | manufacturing process of a cutting tool blade |
| EP1985726A1 (en) * | 2007-04-27 | 2008-10-29 | WMF Aktiengesellschaft | Cutter tool with a cutting edge reinforced with hard material |
| DE102011050601A1 (en) * | 2011-05-24 | 2012-11-29 | Heusch Gmbh & Co. Kg | Knife and cutting device and method for cutting |
| DE102012200425A1 (en) * | 2012-01-12 | 2013-07-18 | Heusch Gmbh & Co. Kg | Knife and method for its production |
| DE202013008594U1 (en) * | 2013-09-27 | 2015-01-09 | Weil Engineering Gmbh | Cutting or punching tool |
| JP6372258B2 (en) * | 2014-09-01 | 2018-08-15 | 株式会社Ihi | Finishing method of blade and blade |
Family Cites Families (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| LU34279A1 (en) * | 1955-03-28 | |||
| US3618654A (en) * | 1969-08-28 | 1971-11-09 | Bandag Inc | High-speed cutting blade |
| FR2038992A5 (en) * | 1970-03-16 | 1971-01-08 | Terrin Ateliers | |
| CA955127A (en) * | 1970-08-26 | 1974-09-24 | Teijin Limited | Knives for the gru-gru cutter |
| CA1177383A (en) * | 1980-06-19 | 1984-11-06 | Ernest H. Roberts | Process for cutting and perforating plastic film |
| DE3139871A1 (en) * | 1981-10-07 | 1983-04-21 | Busatis-Werke GmbH u. Co KG, 5630 Remscheid | Coated cutting blades or fretting parts |
| JPS58177238A (en) * | 1982-04-05 | 1983-10-17 | Toshiba Corp | Manufacture of edged tool |
| US4653373A (en) * | 1986-01-08 | 1987-03-31 | Gerber Scientific Inc. | Knife blade and method for making same |
| JP2736525B2 (en) * | 1987-09-14 | 1998-04-02 | バブコツク日立株式会社 | Spray method |
| JPH01190386A (en) * | 1988-01-26 | 1989-07-31 | Kawatetsu Techno Res Corp | Cooking cutter |
| JPH04310325A (en) * | 1991-04-05 | 1992-11-02 | O S G Kk | Manufacture of hard film covered high speed steel |
| GB9108759D0 (en) * | 1991-04-24 | 1991-06-12 | Mcphersons Ltd | Knife blades |
| GB9208952D0 (en) * | 1992-04-24 | 1992-06-10 | Mcphersons Ltd | Knife blades |
-
1994
- 1994-10-22 DE DE4437911A patent/DE4437911A1/en not_active Withdrawn
-
1995
- 1995-09-28 KR KR1019950032504A patent/KR960013588A/en not_active Application Discontinuation
- 1995-10-06 EP EP95115744A patent/EP0707921B1/en not_active Expired - Lifetime
- 1995-10-06 DE DE59508888T patent/DE59508888D1/en not_active Expired - Fee Related
- 1995-10-19 JP JP7271543A patent/JPH08206989A/en not_active Withdrawn
- 1995-10-20 CA CA002161031A patent/CA2161031A1/en not_active Abandoned
- 1995-10-23 BR BR9504506A patent/BR9504506A/en not_active Application Discontinuation
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6422110B1 (en) | 1999-08-12 | 2002-07-23 | C & E. Fein Gmbh & Co. | Cutting knife for severing tough elastic materials and production method therefor |
| US8505414B2 (en) | 2008-06-23 | 2013-08-13 | Stanley Black & Decker, Inc. | Method of manufacturing a blade |
| EP2527492A1 (en) * | 2010-01-20 | 2012-11-28 | IHI Corporation | Cutting edge structure for cutting tool, and cutting tool with the cutting edge structure |
| US20120317822A1 (en) * | 2010-01-20 | 2012-12-20 | Ihi Corporation | Cutting edge structure for cutting tool, and cutting tool with cutting edge structure |
| EP2527492A4 (en) * | 2010-01-20 | 2014-04-16 | Ihi Corp | Cutting edge structure for cutting tool, and cutting tool with the cutting edge structure |
| US8769833B2 (en) | 2010-09-10 | 2014-07-08 | Stanley Black & Decker, Inc. | Utility knife blade |
| AU2011202496B2 (en) * | 2010-09-10 | 2015-12-17 | Stanley Black & Decker, Inc. | Utility knife blade |
| US9393984B2 (en) | 2010-09-10 | 2016-07-19 | Stanley Black & Decker, Inc. | Utility knife blade |
| EP2428310B1 (en) * | 2010-09-10 | 2017-01-18 | Stanley Black & Decker, Inc. | Utility knife blade |
| TWI569937B (en) * | 2010-09-10 | 2017-02-11 | 史坦利百工公司 | Utility knife blade |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH08206989A (en) | 1996-08-13 |
| EP0707921A3 (en) | 1997-07-23 |
| BR9504506A (en) | 1997-05-20 |
| KR960013588A (en) | 1996-05-22 |
| EP0707921B1 (en) | 2000-12-06 |
| DE59508888D1 (en) | 2001-01-11 |
| DE4437911A1 (en) | 1996-04-25 |
| EP0707921A2 (en) | 1996-04-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA2161031A1 (en) | Knife and method for manufacturing a knife | |
| EP0567300B1 (en) | Knife blades | |
| DE19713519C2 (en) | Process for the pretreatment and coating of aluminum bore surfaces | |
| EP0635326B1 (en) | Abrasive tool insert | |
| RU2108235C1 (en) | Method of formation of razor blades and razor blade | |
| EP0691167B1 (en) | Abrasive tool insert | |
| EP0920363B1 (en) | A method of producing a cutting tool insert | |
| EP2719511B1 (en) | Scribing wheel, and scribing method | |
| US20120037140A1 (en) | Fixed abrasive sawing wire with a rough interface between core and outer sheath | |
| KR0149521B1 (en) | Knife blades | |
| US6422110B1 (en) | Cutting knife for severing tough elastic materials and production method therefor | |
| Brown et al. | Erosion of α-Fe by spherical glass particles | |
| US3248189A (en) | Abrading tool structure | |
| KR19980703399A (en) | knife | |
| US5759641A (en) | Method of applying strengthening coatings to metallic or metal-containing surfaces | |
| Luo et al. | Effects of diamond grain characteristics on sawblade wear | |
| Griffiths et al. | The erosion of steel surfaces by grit-blasting as a preparation for plasma spraying | |
| Griffiths et al. | A definition of the topography of grit-blasted surfaces for plasma sprayed alumina coatings | |
| JPH04231429A (en) | Method for grinding for manufacturing filament-reinforced composite | |
| US3951012A (en) | Process for making a file and article resulting therefrom | |
| EP1573125B1 (en) | Wear resistant coating blade or a corresponding blade for the treatment of a paper web | |
| JP3402849B2 (en) | Blade and blade manufacturing method | |
| Bradbury et al. | Impact of surface engineering technologies on the performance and life of multi-point cutting tools | |
| JPS60165340A (en) | Selectively and partially modified sintered alloy | |
| JPS6317613Y2 (en) |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued | ||
| FZDE | Discontinued |
Effective date: 20001020 |