A forging method of tungsten-molybdenum bimetallic butterfly target

Abstract

The present invention discloses a forging method of a tungsten-molybdenum bimetallic butterfly target, which relates to the technical field of refractory metal processing, and comprises the following steps: placing a sintered billet of a tungsten-molybdenum bimetallic layer in a hydrogen furnace for heating; preheating a butterfly forging die; placing the heated sintered billet of a tungsten-molybdenum bimetallic layer in a heated butterfly forging die for preliminary forging to obtain a preliminary forging billet; replacing the limiting ring of the butterfly forging die, placing the preliminary forging billet in the butterfly forging die again for a second forging to obtain a secondary forging target; cutting the secondary forging target to obtain a tungsten-molybdenum bimetallic butterfly target. The present application improves the processing accuracy and density of the tungsten-molybdenum bimetallic butterfly target by setting and replacing the limiting ring of the butterfly forging die, combined with a heating process, and performing two forgings on the sintered billet of the tungsten-molybdenum bimetallic layer.

Description

Technical Field

[0001] The present application relates to the technical field of refractory metal processing, and in particular to a forging method of a tungsten-molybdenum bimetallic butterfly target. Background Art

[0002] Tungsten-molybdenum bimetallic butterfly target is the main component of medical CT target disk, which plays the role of supporting the target disk and generating X-rays. Generally, the density of tungsten-molybdenum bimetallic butterfly target is required to reach more than 98%. It is difficult to achieve the density standard by traditional ordinary sintering. If the density is improved by hot processing, there will be problems such as cracking of the bimetallic layer interface and difficulty in forging deformation. Therefore, it is necessary to study the forging method of tungsten-molybdenum bimetallic butterfly target.

[0003] In the prior art, Chinese patent CN110293223A discloses a method for preparing a butterfly-shaped molybdenum-tungsten bimetallic composite rotating target, which comprises: first, filling Mo-W powder into a cavity formed by a cylinder and a lower mold of a butterfly-shaped graphite mold, and pre-pressing with an upper mold to form a molybdenum-tungsten powder layer; second, filling tungsten powder on the molybdenum-tungsten powder layer to form a tungsten powder layer, and then covering the upper mold for vacuum hot pressing and sintering to obtain a rough butterfly-shaped molybdenum-tungsten bimetallic composite rotating target; and third, heat-treating the rough butterfly-shaped molybdenum-tungsten bimetallic composite rotating target, and machining to obtain a butterfly-shaped molybdenum-tungsten bimetallic composite rotating target.

[0004] Chinese patent CN1093828A discloses a method for manufacturing a disc-shaped molybdenum-based tungsten target, which adopts a powder metallurgy process to make a blank, and then sinter and forge it once. A disc-shaped mold is used for composite feeding, pressed once, sintered in hydrogen or vacuum, and forged once under a certain pressure to form a disc-shaped molybdenum-based tungsten target.

[0005] However, the processing accuracy and density of the above-mentioned prior art tungsten-molybdenum bimetallic butterfly target are relatively poor. Summary of the invention

[0006] The present application provides a forging method for a tungsten-molybdenum bimetallic butterfly target material, which is used to solve the problems of poor processing accuracy and density in the existing tungsten-molybdenum bimetallic butterfly target material preparation technology.

[0007] On the one hand, the present application provides a forging method of a tungsten-molybdenum bimetallic butterfly target, comprising the following steps: Step 1: Place the tungsten-molybdenum bimetallic layer sintered blank into a hydrogen furnace for heating.

[0008] Step 2: preheating the butterfly forging die, wherein the butterfly forging die is provided with several kinds of limit rings.

[0009] Step three, placing the heated tungsten-molybdenum bimetallic layer sintered blank into a heated butterfly forging die for preliminary forging to obtain a preliminary forging blank.

[0010] Step 4: Replace the limiting ring of the butterfly forging die, put the preliminary forging blank into the butterfly forging die again for a second forging to obtain a secondary forging target.

[0011] Step five, cutting the secondary forging target material according to a preset target material processing size to obtain a tungsten-molybdenum bimetallic butterfly target material.

[0012] In a possible implementation, in step 1, the heating temperature of the tungsten-molybdenum bimetallic layer sintered blank in a hydrogen furnace is 1400-1800° C., and the insulation time is 30-60 minutes.

[0013] In a possible implementation, in step 2, the butterfly forging die is preheated to 300-450°C.

[0014] In a possible implementation, in step three, the pressure of the preliminary forging is 500 MPa, and the deformation of the preliminary forging is controlled to be 6%-12% by selecting a limit ring.

[0015] In a possible implementation, in step three, after obtaining the preliminary forging blank, the preliminary forging blank is placed in a hydrogen furnace for heating, the heating temperature is consistent with that in step one, and the insulation time is 30 minutes.

[0016] In a possible implementation, in step 4, before the second forging, the butterfly forging die is preheated in the same manner as in step 2.

[0017] In a possible implementation, in step 4, the pressure of the second forging is 300 MPa, and the deformation of the second forging is controlled to be 3%-6% by replacing the limit ring.

[0018] In a possible implementation, the initial forging in step three and the secondary forging in step four both adopt static pressure forging technology.

[0019] In one possible implementation, step five includes: leveling the bimetallic layer interface of the secondary forging target material so that the concentricity is less than 0.02 mm on the same circumferential plane, and cutting the leveled secondary forging target material according to a preset target material processing size to obtain a tungsten-molybdenum bimetallic butterfly target material.

[0020] In a possible implementation, in step five, the diameter of the tungsten-molybdenum bimetallic butterfly target is 100-250 mm.

[0021] A forging method of a tungsten-molybdenum bimetallic butterfly target in the present application has the following advantages: By setting and replacing the limit ring of the butterfly forging die and combining it with the heating process, the sintered billet of the tungsten-molybdenum bimetallic layer is forged twice, which improves the processing accuracy and density of the tungsten-molybdenum bimetallic butterfly target. The density is above 98%. The two forgings also improve the yield and material utilization rate.

[0022] By heating the sintered billet of the tungsten-molybdenum bimetallic layer, preheating the butterfly forging die, and controlling the heating parameters, the plasticity of the material is improved and forging cracking is avoided.

[0023] By heating the preliminary forging billet, preheating the butterfly forging die, and controlling the heating parameters, the material grain structure is refined, and the density and material plasticity are further improved.

[0024] By adopting static pressure forging technology, cracking caused by excessive forging impact force is avoided and processing reliability is improved.

[0025] The diameter of the tungsten-molybdenum bimetallic butterfly target finally obtained in the present application is 100-250 mm, and has good size adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 A schematic diagram of a process forging a tungsten-molybdenum bimetallic butterfly target provided in an embodiment of the present application; Figure 2 A schematic diagram of a secondary forging target material obtained by a second forging using a butterfly forging die provided in an embodiment of the present application.

[0028] Description of reference numerals: 1-upper die head, 2-lower die cavity, 3-limiting ring, 4-secondary forging target. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0030] like Figure 1 to Figure 2As shown, the embodiment of the present application provides a forging method of a tungsten-molybdenum bimetallic butterfly target, comprising the following steps: Step 1: Place the tungsten-molybdenum bimetallic layer sintered blank into a hydrogen furnace for heating.

[0031] Step 2: preheating the butterfly forging die, wherein the butterfly forging die is provided with several types of limit rings 3.

[0032] Step three, placing the heated tungsten-molybdenum bimetallic layer sintered blank into a heated butterfly forging die for preliminary forging to obtain a preliminary forging blank.

[0033] Step 4: Replace the limiting ring 3 of the butterfly forging die, put the primary forging blank into the butterfly forging die again for a second forging, and obtain a secondary forging target 4.

[0034] Step five: cutting the secondary forging target material 4 according to the preset target material processing size to obtain a tungsten-molybdenum bimetallic butterfly target material.

[0035] Specifically, the butterfly forging die includes an upper die head 1, a lower die cavity 2 and a limit ring 3, wherein the lower end of the upper die head 1 matches the bottom shape of the lower die cavity 2 and both are butterfly-shaped, there are several types of limit rings 3, and different limit rings 3 can meet different deformation requirements of forging, and the secondary forging target material 4 includes an upper and lower layer, wherein the upper layer is a tungsten metal layer, and the lower layer is a molybdenum metal layer.

[0036] Embodiment 1: In this embodiment, in step 1, the heating temperature of the sintered billet of the tungsten-molybdenum bimetallic layer in the hydrogen furnace is 1400° C., and the insulation time is 30 minutes.

[0037] In step 2, the butterfly forging die is preheated to 300°C.

[0038] In step three, the initial forging pressure is 500 MPa, and the initial forging deformation is controlled to 6% by selecting the limit ring 3.

[0039] In step three, after obtaining the preliminary forging blank, the preliminary forging blank is placed in a hydrogen furnace for heating. The heating temperature is consistent with that in step one, and the insulation time is 30 minutes.

[0040] In step 4, before the second forging, the butterfly forging die is preheated in the same manner as in step 2.

[0041] In step 4, the pressure of the second forging is 300 MPa, and the deformation of the second forging is controlled to be 3% by replacing the limit ring 3.

[0042] The initial forging in step 3 and the secondary forging in step 4 both adopt static pressure forging technology.

[0043] Step five includes: leveling the bimetallic layer interface of the secondary forging target 4 so that the concentricity is less than 0.02 mm on the same circumferential surface, and cutting the leveled secondary forging target 4 according to the preset target processing size to obtain a tungsten-molybdenum bimetallic butterfly target.

[0044] The diameter of the tungsten-molybdenum bimetallic butterfly target obtained in Example 1 is 250 mm, and the density is greater than 98%.

[0045] Embodiment 2: In this embodiment, in step 1, the heating temperature of the sintered billet of the tungsten-molybdenum bimetallic layer in the hydrogen furnace is 1800° C., and the insulation time is 60 minutes.

[0046] In step 2, the butterfly forging die is preheated to 450°C.

[0047] In step three, the initial forging pressure is 500 MPa, and the initial forging deformation is controlled to be 12% by selecting the limit ring 3.

[0048] In step three, after obtaining the preliminary forging blank, the preliminary forging blank is placed in a hydrogen furnace for heating. The heating temperature is consistent with that in step one, and the insulation time is 30 minutes.

[0049] In step 4, before the second forging, the butterfly forging die is preheated in the same manner as in step 2.

[0050] In step 4, the pressure of the second forging is 300 MPa, and the deformation of the second forging is controlled to be 6% by replacing the limit ring 3.

[0051] The initial forging in step 3 and the secondary forging in step 4 both adopt static pressure forging technology.

[0052] Step five includes: leveling the bimetallic layer interface of the secondary forging target 4 so that the concentricity is less than 0.02 mm on the same circumferential surface, and cutting the leveled secondary forging target 4 according to the preset target processing size to obtain a tungsten-molybdenum bimetallic butterfly target.

[0053] The diameter of the tungsten-molybdenum bimetallic butterfly target obtained in Example 2 is 100 mm, and the density is greater than 98%.

[0054] Embodiment three: In this embodiment, in step 1, the heating temperature of the sintered billet of the tungsten-molybdenum bimetallic layer in the hydrogen furnace is 1600° C., and the insulation time is 50 minutes.

[0055] In step 2, the butterfly forging die is preheated to 420°C.

[0056] In step three, the initial forging pressure is 500 MPa, and the initial forging deformation is controlled to be 11% by selecting the limit ring 3.

[0057] In step three, after obtaining the preliminary forging blank, the preliminary forging blank is placed in a hydrogen furnace for heating. The heating temperature is consistent with that in step one, and the insulation time is 30 minutes.

[0058] In step 4, before the second forging, the butterfly forging die is preheated in the same manner as in step 2.

[0059] In step 4, the pressure of the second forging is 300 MPa, and the deformation of the second forging is controlled to be 4% by replacing the limit ring 3.

[0060] The initial forging in step 3 and the secondary forging in step 4 both adopt static pressure forging technology.

[0061] Step five includes: leveling the bimetallic layer interface of the secondary forging target 4 so that the concentricity is less than 0.02 mm on the same circumferential surface, and cutting the leveled secondary forging target 4 according to the preset target processing size to obtain a tungsten-molybdenum bimetallic butterfly target.

[0062] The diameter of the tungsten-molybdenum bimetallic butterfly target obtained in Example 3 is 150 mm, and the density is greater than 98%.

[0063] Embodiment 4: In this embodiment, in step 1, the heating temperature of the sintered billet of the tungsten-molybdenum bimetallic layer in the hydrogen furnace is 1700° C., and the insulation time is 40 minutes.

[0064] In step 2, the butterfly forging die is preheated to 370°C.

[0065] In step three, the initial forging pressure is 500 MPa, and the initial forging deformation is controlled to 8% by selecting the limit ring 3.

[0066] In step three, after obtaining the preliminary forging blank, the preliminary forging blank is placed in a hydrogen furnace for heating. The heating temperature is consistent with that in step one, and the insulation time is 30 minutes.

[0067] In step 4, before the second forging, the butterfly forging die is preheated in the same manner as in step 2.

[0068] In step 4, the pressure of the second forging is 300 MPa, and the deformation of the second forging is controlled to be 4% by replacing the limit ring 3.

[0069] The initial forging in step 3 and the secondary forging in step 4 both adopt static pressure forging technology.

[0070] Step five includes: leveling the bimetallic layer interface of the secondary forging target 4 so that the concentricity is less than 0.02 mm on the same circumferential surface, and cutting the leveled secondary forging target 4 according to the preset target processing size to obtain a tungsten-molybdenum bimetallic butterfly target.

[0071] The diameter of the tungsten-molybdenum bimetallic butterfly target obtained in Example 4 is 200 mm, and the density is greater than 98%.

[0072] The embodiment of the present application sets and replaces the limit ring 3 of the butterfly forging die, combines the heating process, and performs two forgings on the sintered billet of the tungsten-molybdenum bimetallic layer, thereby improving the processing accuracy and density of the tungsten-molybdenum bimetallic butterfly target material, with the density being above 98%. The two forgings also improve the yield rate and material utilization rate.

[0073] By heating the sintered billet of the tungsten-molybdenum bimetallic layer, preheating the butterfly forging die, and controlling the heating parameters, the plasticity of the material is improved and forging cracking is avoided.

[0074] By heating the preliminary forging billet, preheating the butterfly forging die, and controlling the heating parameters, the material grain structure is refined, and the density and material plasticity are further improved.

[0075] By adopting static pressure forging technology, cracking caused by excessive forging impact force is avoided and processing reliability is improved.

[0076] The diameter of the tungsten-molybdenum bimetallic butterfly target finally obtained in the present application is 100-250 mm, and has good size adaptability.

[0077] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0078] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A forging method for a tungsten-molybdenum bimetallic butterfly target, characterized in that: The following steps are involved: Step 1: placing the sintered billet of the tungsten-molybdenum bimetallic layer into a hydrogen furnace for heating; Step 2, preheating the butterfly forging die, wherein the butterfly forging die is provided with several types of limit rings; Step 3, placing the heated tungsten-molybdenum bimetallic layer sintered blank into a heated butterfly forging die for preliminary forging to obtain a preliminary forging blank; Step 4, replacing the limiting ring of the butterfly forging die, and placing the preliminary forging blank into the butterfly forging die again for forging for the second time to obtain a secondary forging target; Step five, cutting the secondary forging target material according to a preset target material processing size to obtain a tungsten-molybdenum bimetallic butterfly target material.

2. The forging method of a tungsten-molybdenum bimetallic butterfly target according to claim 1, characterized in that: In step 1, the heating temperature of the sintered billet of the tungsten-molybdenum bimetallic layer in the hydrogen furnace is 1400-1800° C., and the insulation time is 30-60 minutes.

3. The forging method of a tungsten-molybdenum bimetallic butterfly target according to claim 1, characterized in that: In step 2, the butterfly forging die is preheated to 300-450°C.

4. The forging method of a tungsten-molybdenum bimetallic butterfly target according to claim 1, characterized in that: In step three, the pressure of the preliminary forging is 500 MPa, and the deformation of the preliminary forging is controlled to be 6%-12% by selecting a limit ring.

5. The forging method of a tungsten-molybdenum bimetallic butterfly target according to claim 1, characterized in that: In step three, after obtaining the preliminary forging blank, the preliminary forging blank is placed in a hydrogen furnace for heating. The heating temperature is consistent with that in step one, and the insulation time is 30 minutes.

6. The forging method of a tungsten-molybdenum bimetallic butterfly target according to claim 1, characterized in that: In step 4, before the second forging, the butterfly forging die is preheated in the same manner as in step 2.

7. The forging method of a tungsten-molybdenum bimetallic butterfly target according to claim 1, characterized in that: In step 4, the pressure of the second forging is 300 MPa, and the deformation of the second forging is controlled to be 3%-6% by replacing the limit ring.

8. The forging method of a tungsten-molybdenum bimetallic butterfly target according to claim 1, characterized in that: The initial forging in step 3 and the secondary forging in step 4 both adopt static pressure forging technology.

9. The forging method of a tungsten-molybdenum bimetallic butterfly target according to claim 1, characterized in that: Step five includes: leveling the bimetallic layer interface of the secondary forging target material so that the concentricity is less than 0.02 mm on the same circumferential surface, and cutting the leveled secondary forging target material according to a preset target material processing size to obtain a tungsten-molybdenum bimetallic butterfly target material.

10. The forging method of a tungsten-molybdenum bimetallic butterfly target according to claim 1, characterized in that: In step five, the diameter of the tungsten-molybdenum bimetallic butterfly target is 100-250 mm.

Images