JPH0663994A - Nozzle for injection molding machine - Google Patents

Abstract

PURPOSE:To obtain a nozzle for an injection molding machine having high hardness and toughness, excellent wear resistance, corrosion resistance, durability and low manufacturing cost by using special cermet alloy as a material. CONSTITUTION:A cermet alloy has a hard layer containing one or more types of MC, MN, MCN by representing one or more types of transition metals of group 4a, 5a, 6a of the Periodic Table by M and W-Co-B compound as main ingredients and/or a hard layer containing an Mo-Co-B compound as a main ingredient as well as a coupling phase of Co as a main ingredient. The metal Co in the phase is desirably 7wt.% or less. If the hard phase contains WC and the W-Co-B compound and/or the Mo-Co-B compound, the metal Co in the phase is desirably 3.5% or less. This alloy is manufactured by mixing powder of one or more types of the MC, MN, MCN, the WB and/or MoB and powder of the Co, molding the mixture, and sintering it in a non-oxidative atmosphere.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nozzle for an injection molding machine for injection molding an injection molding material such as plastic, ceramic or metal powder, which is particularly easy to sinter and has extremely high hardness and toughness. The present invention relates to a nozzle for an injection molding machine, which uses a cermet alloy having good characteristics.

[0002]

2. Description of the Related Art For example, in plastic injection molding, a thermoplastic or thermosetting resin is heated and fluidized in a cylinder 2 having a nozzle 1 at the tip as shown in FIG. It is carried out by injecting it into the mold (not shown) arranged in front of the nozzle 1 from the nozzle 1 at the tip. It is necessary that the nozzle 1 has excellent wear resistance against high pressure and high flow rate of the molten plastic and also has corrosion resistance to corrosive gas such as fluorine gas generated from the molten plastic.

A nozzle for such an injection molding machine is disclosed in Japanese Patent Laid-Open No.
No. 1-186406 is 5-5 by hot isostatic pressing.
A nozzle for an injection molding machine in which the inner diameter of the nozzle is coated with a Co-based or Ni-based alloy containing 0 wt% WC (tungsten carbide) is disclosed. JP-A-1-272704 discloses hard particles, Co-based and Ni-based particles. There is disclosed a nozzle for an injection molding machine, which is made of at least one of the self-fluxing alloys and is coated with an alloy containing 50 to 70 wt% of hard material particles.

[0004]

However, the above conventional nozzles for injection molding machines have the following problems. That is, in the method disclosed in JP-A-61-186406, there is a problem that voids may be generated in the sintered layer to cause a decrease in hardness, and that the manufacturing cost is high because it is manufactured by hot isostatic pressing. is there.

Further, in the one disclosed in Japanese Patent Application Laid-Open No. 1-272704, the hard particles containing 50 to 70 wt% and Co are insufficiently bonded to each other, resulting in insufficient toughness and being subjected to heat cycle in the actual use process. There is a problem in durability because it may be damaged by thermal shock. Further, the above-mentioned JP-A-61-186406 and JP-A-1-27270.
The nozzles for injection molding machines shown in No. 4 are merely compositions having a substantially uniform composition, and in that respect, there is room for further improvement in terms of hardness, toughness, that is, wear resistance and durability.

The present invention has been made in view of the above problems in the prior art, and has high hardness and toughness, good wear resistance and corrosion resistance, excellent durability, and low manufacturing cost. An object is to provide a nozzle for an injection molding machine.

[0007]

As a result of various studies to achieve the above object, the present inventor has found that WB powder, Co powder and / or MoB powder, and MC, MN and MCN.
1 or 2 or more (M is a periodic table 4a, 5a, 6
A cermet alloy obtained by mixing and sintering a powder of one or more kinds of transition metal elements of the group a-as in the following description) is one or more kinds of MC, MN and MCN and W-.
The cermet alloy is composed of a hard phase mainly composed of a Co-B compound and / or a Mo-Co-B compound and a binder phase mainly composed of Co. The cermet alloy has high toughness and hardness, and is used as a nozzle for an injection molding machine. It has come to be found that it satisfies both the wear resistance and corrosion resistance characteristics of

In addition, the above-mentioned WB powder and / or Mo
Further investigation of a cermet alloy obtained by mixing and sintering B powder, Co powder, and one or more powders of MC, MN, and MCN revealed the following. The hard phase mainly composed of one or more of MC, MN and MCN is one or two of MC, MN and MCN.
More than one species and (M, W) (B, C) and / or (M,
Mo) (B, C) and / or (M, W) (B, N)
And / or (M, Mo) (B, N) and / or (M, W) (B, CN) and / or (M, Mo)
(B, CN), one or more of MC, MN and MCN are used as the core, and (M, W) (B, C) and / or (M, Mo) (B, C) and / Or (M, W) (B, N) and / or (M, Mo)
(B, N) and / or (M, W) (B, CN) and / or (M, Mo) (B, CN) may be present on the outer peripheral portion to form a core structure. The hard phase mainly composed of the W-Co-B compound is CoW.
B and CoW ₂ B ₂ and the core of CoW ₂ B ₂ and C
A core structure composed of the outer peripheral part of oWB may be formed, and the hard phase mainly composed of the Mo—Co—B compound is Co.
Consists MoB and CoMo ₂ B _2, often form a cored structure consisting of the core portion and the outer peripheral portion of the CoMo ₂ B ₂ of CoMoB.

The nozzle for an injection molding machine according to the invention of the present application is based on the above findings, and according to the invention of the present application, one or more kinds of MC, MN and MCN and W.
Provided is a nozzle for an injection molding machine, which uses a cermet alloy including a hard layer mainly containing a —Co—B compound and / or a Mo—Co—B compound and a binder phase mainly containing Co.

The metallic Co in the binder phase is preferably 7% by weight or less. W-Co-B compound and / or Mo-
This is because if the metallic Co that does not contribute to the formation of the Co-B compound exceeds 7% by weight, the hardness is lowered.

According to the invention of the present application, a hard phase mainly containing one or more of MC, MN, and MCN and a W-Co-B compound and / or a Mo-Co-B compound are mainly contained. A sintered body composed of a hard phase and a binder phase mainly composed of Co, and a hard phase mainly composed of one kind or two or more kinds of MC, MN and MCN is one kind or two of MC, MN and MCN. More than species, and (M, W) (B,
C), (M, W) (B, N), (M, W) (B, CN)
One or more of and / or (M, Mo)
(B, C), (M, Mo) (B, N), (M, Mo)
Provided is a nozzle for an injection molding machine, which uses a cermet alloy composed of one or more of (B, CN).

Further, according to the invention of the present application, a hard phase mainly containing one or more of MC, MN and MCN and a hard phase mainly containing a W-Co-B compound and / or a Mo-Co-B compound. And a W-Co-B compound and / or a sintered body comprising a binder phase containing Co as a main component.
Alternatively, the hard phase mainly composed of the Mo-Co-B compound is C
oWB and CoW ₂ B ₂ and / or CoMoB and C
Provided is a nozzle for an injection molding machine using a cermet alloy composed of oMo ₂ B ₂ .

In addition, according to the invention of the present application, MC, MN
And a hard phase mainly composed of one or more kinds of MCN, a hard phase mainly composed of a W-Co-B compound and / or a Mo-Co-B compound, and a sintering composed of a binder phase mainly composed of Co. The body, one of MC, MN and MCN
The hard phase mainly composed of one or more kinds is one or more kinds of MC, MN and MCN, and (M, W)
(B, C), (M, W) (B, N) and (M, W)
One or more of (B, CN) and / or one of (M, Mo) (B, C), (M, Mo) (B, N) and (M, Mo) (B, CN) or consists of two or more, made of hard phase composed mainly of W-Co-B compound is made CoWB and _{CoW 2 B 2, Mo-Co} -B
The hard phase mainly composed of compounds is CoMoB and CoMo.
_A nozzle for an injection molding machine using a cermet alloy composed of ₂ B ₂ is provided.

Furthermore, according to the present invention, a hard phase containing TiC as a main component, a hard phase containing W-Co-B compound as a main component and / or a hard phase containing Mo-Co-B as a main component, and Co as a main component. The hard phase mainly composed of TiC is TiC and (T
i, W) (B, C) and / or (Ti, Mo)
A nozzle for an injection molding machine using a cermet alloy composed of (B, C) is provided.

Furthermore, according to the present application, a hard phase containing TiC as a main component and a hard phase containing W-Co-B compound as a main component and / or a hard phase containing Mo-Co-B compound as a main component and Co as a main component. A hard phase mainly composed of a W—Co—B compound is a Co-based sintered body.
A nozzle for an injection molding machine using a cermet alloy composed of WB and CoW ₂ B ₂ and mainly composed of a Mo—Co—B compound is provided, which uses a cermet alloy composed of CoMoB and CoMo ₂ B ₂ .

In addition, according to the present application, a hard phase mainly composed of TiC and / or a hard phase mainly composed of a W—Co—B compound and / or a hard phase mainly composed of a Mo—Co—B compound,
And a hard phase mainly composed of TiC, which is a sintered body composed of a binder phase mainly composed of Co, and TiC and (Ti,
W) (B, C) and / or (Ti, Mo) (B,
Consist C), hard phase composed mainly of W-Co-B compound is made CoWB and _{CoW 2 B 2, Mo-Co} -B
The hard phase mainly composed of compounds is CoMoB and CoMo.
_A nozzle for an injection molding machine using a cermet alloy composed of ₂ B ₂ is provided.

Furthermore according to the present application WC and WC
Provided is a nozzle for an injection molding machine using a cermet alloy composed of a hard phase containing an o-B compound and / or a Mo-Co-B compound as a main component, and a binder phase containing Co as a main component. The metallic Co of the binder phase is preferably 3.5% by weight or less.

The cermet alloy applied to the nozzle for the injection molding machine of the present invention is a raw material powder containing 15 to 45% by volume of WB and / or MoB and 5 to 20% by volume of Co.
After the remaining MC, MN, and MCN are mixed or molded with one or more kinds (M is one or more kinds of transition metal elements of groups 4a, 5a, and 6a of the periodic table), the sintering temperature is 1300.
It is manufactured by sintering under conditions of ˜1600 ° C. and sintering time of 10 to 120 minutes.

The cermet alloy applied to the nozzle for an injection molding machine of the invention of the present application is a raw material powder containing 15 to 45% by volume of WB and / or MoB, 5 to 25% by volume of Co, and the remaining TiC mixed and molded. After sintering temperature 1300
It is manufactured by sintering under conditions of ˜1600 ° C. and sintering time of 10 to 120 minutes. In addition, the cermet alloy applied to the nozzle for the injection molding machine of the invention of the present application is a raw material powder of WB.
And / or 10 to 40% by volume of MoB and 5 to Co.
20% by volume and the balance WC are mixed and molded, and then sintered under the conditions of a sintering temperature of 1300 to 1600 ° C. and a sintering time of 10 to 120 minutes.

Further, in order to manufacture the cermet alloy applied to the nozzle for the injection molding machine of the present invention, MC and MN are used.
And one or more powders of MCN, WB and / or
Alternatively, MoB and Co powders may be mixed and molded, and sintered in a non-oxidizing atmosphere, and it is not necessary to take measures such as hydrostatic sintering.

One or two of MC, MN and MCN
When mixing the powders of one or more kinds and the powders of WB and / or MoB, Co, the mixing ratio is preferably within the range of Table 1 for each component.

[0022]

[Table 1]

At this compounding ratio, WB and / or M
If oB exceeds 45% by volume, uniform sintering tends to be difficult. Further, when Co is less than 5% by volume, strength and toughness decrease. This is because the W-Co-B composite layer and / or Mo-Co-B produced by the reaction of WB and / or MoB with Co when the amount of Co decreases.
It is presumed that this is because it is difficult to form the composite layer. Further, when Co is more than 25% by volume, the binder phase becomes excessive and the hardness of the cermet alloy decreases. In addition, weight% of the compounding ratio indicates the value when TiC is selected as the MC.

Of the cermet alloys used in the nozzle for an injection molding machine of the present invention having the above blending ratio, the composition of the alloy in which, for example, TiC is selected as MC is in the range shown in Table 2 or Table 3.

[0025]

[Table 2]

If the particle size of the powder is too small, the amount of oxygen in the powder increases, and pores are likely to occur in the sintered body. Conversely, if the particle size of the powder increases, the activity of the powder decreases and it becomes difficult to proceed with sintering. MC, MN and M blended from the above viewpoints
The particle size of one or more powders of CN is 0.5-45.
μm, especially about 0.7-10 μm is preferable. The particle size of WB and / or MoB is preferably 0.8-10 μm, more preferably 1.0-5.0 μm. Co may be about 10.0 μm or less.

This compact can be sintered by a pressureless sintering method. The atmosphere is preferably a non-oxidizing atmosphere such as nitrogen, argon or vacuum. Of course, it can be sintered by hot pressing or HIP, but a high-density sintered body can be obtained without using such a pressure sintering method. When the pressureless sintering method is used, the sintering temperature is preferably 1300-1600 ° C., particularly 1400-1500 ° C., and the sintering time is 10
-120 minutes, especially 30-90 minutes are preferred. In particular, if the sintering temperature is less than 1300 ° C, the sintering does not proceed sufficiently and pores tend to remain, while if it exceeds 1600 ° C, the grain growth of the hard phase becomes remarkable, which is not preferable. If the sintering time is less than 10 minutes, the pores tend to remain, while if it exceeds 120 minutes, grain growth of the hard phase tends to occur, which is not preferable.

[0028]

In the cermet alloy used in the nozzle for an injection molding machine of the present invention, Co melts during sintering and promotes sintering to achieve densification, and a composite material in which hard particles are strongly bonded to Co. Become. Moreover, as a result of the study by the present invention, this Co is simply MC, MN and MCN particles and W-
In addition to filling the gaps between the B compound particles and / or the Mo-B compound particles, a part of Co reacts with WB and / or MoB and enters the inside of the WB and / or MoB particles, and CoW ₂ B ₂ and / or CoMoB is formed, and CoWB is formed on the surface of the CoW ₂ B ₂ particles.
It was found that the phase formed a CoMoB phase on the surface portion of the CoMo ₂ B ₂ particles. Since the W-Co-B-based composite phase and / or the Mo-Co-B-based composite phase has a higher affinity for the Co matrix phase than the WB single phase and / or the MoB single phase, the injection of the invention of the present application In the cermet alloy used for the molding machine nozzle, the bond strength between the W-Co-B phase and / or the Mo-Co-B phase and the Co phase is high. In the W-Co-B composite phase, WB particles are Co
Reacts in the sintering process with the core made of CoW ₂ B ₂ and CoW
It often has a core structure having an outer skin part made of B, and the Mo-Co-B composite phase reacts with Mo in the sintering process of the MoB particles to form a core part made of CoMo ₂ B ₂ and CoMoB.
There is a case where a cored structure having an outer skin made of

In addition, due to the above-mentioned sintering, a part of WB and / or MoB also reacts with MC, MN and MCN,
(M, W) (B, C), (M, W) (B, N), (M,
W) (B, CN) composite phase and / or (M, Mo)
(B, C), (M, Mo) (B, N), (M, Mo)
Forming a complex phase of (B, CN), MC, MN and MCN
The particles have a cored structure composed of a core part and an outer skin part. This skin phase is a phase containing W and / or Mo and B in a larger amount than in the core. Such {MC, MN and MCN- (M,
W) (B, C), (M, W) (B, N), (M, W)
(B, CN)} cored structure and / or (MC, MN and MCN- (M, Mo) (B, C), (M, Mo)
(B, N), (M, Mo) (B, CN)) Core structure is M
Since the affinity for Co is higher than that for C, MN and MCN phases, MC, MN and MCN particles and Co (M, W)
(B, C) and / or (M, W) (B, N) and / or (M, W) (B, CN) phase and / or (M, Mo) (B, C) and / or (M , Mo)
(B, N) and / or (M, Mo) (B, CN) phases are combined to form a so-called functionally graded structure in which the composition gradually changes from the MC, MN and MCN cores toward the Co side. The bond strength is high.

Further, Co and a part of WB and / or MoB are reacted and melted during the above-mentioned sintering, so that the melting point is lowered, and a sufficiently dense sintered body is obtained without the pressure sintering method. Could be configured.

As described above, the hard particles or the hard particles and the Co matrix phase have a very high binding force, so that the cermet alloy used in the nozzle for an injection molding machine of the present invention has excellent toughness. Further, high hardness MC, MN and MCN are used as the hard particles, and a part of low hardness Co after sintering is a W—Co—B compound and / or M.
Since the o-Co-B compound is formed, the cermet alloy used in the nozzle for the injection molding machine of the present invention has high hardness. As a result of various studies, it was confirmed that the cermet alloy used in the nozzle for an injection molding machine of the present invention has a high Vickers hardness Hv of 1800 or more.

[0032]

【Example】

Example 1 The grain size of the MC, MN and MCN is 0.5 to 10 μm.
WB with the same particle size of 1.0-5.0 μm
And the same 5-10 μm Co as shown in Table 3 (volume%)
Mixed in. 1,500 kgf / cm of these mixtures
Press molding was carried out at a pressure of ² (about 147 × 10 Pa) to obtain a compact having a diameter of 10 mm and a height of 5 mm. This molded body was vacuumed at 1450 ° C, 1500 ° C and 155 ° C, respectively.
It was sintered at 0 ° C. for 1 hour to obtain a cermet alloy used in the nozzle for an injection molding machine of the present invention. Table 3 shows Vickers hardness Hv (1450), Hv corresponding to the above sintering temperature.
(1500) and Hv (1550) and crack resistance CR (1450), CR (1500) and CR
The value of (1550) is also shown. Note that ICP-Co is the value of Co in the binder phase measured by plasma emission analysis. That is, the sintered body was crushed to 325 mesh or less to obtain a sample for analysis, only the metal phase was selectively dissolved in the acid solution, and the non-dissolved powder was filtered and removed from the solution by a filter to remove Co in the solution. It is an analysis. Thereby, the amount of metallic Co remaining in the binder phase of the sintered body can be analyzed. The numbers in the table with () indicate the characteristics of the cermet alloy used for the injection molding machine nozzle of the present invention in comparison with the characteristics of the cermet alloy used for the injection molding machine nozzle of the present invention. It is a comparative example for clarifying.

[0033]

[Table 3]

FIG. 1 is a diagram schematically showing an X-ray diffraction result of a sintered body, which shows WC-30 vol% WB-10 vol% C.
It is an example when the product of No. o was sintered at 1500 ° C. Figure 1
As is apparent from the above, most of Co reacts with WB by sintering, and CoW ₂ B ₂ and CoWB, which are W-Co-B compounds, react.
It can be seen that

Example 2 TiC having a grain size of 0.7 μm was used as the MC, and 0.8
WB of μm and Co of 3.0 μm were mixed according to the formulation shown in Table 4. In addition, Table 4 also shows the blending element amounts as a result of mixing.

[0036]

[Table 4]

The mixture shown in Table 4 above was 1500 kg /
Press molding was performed at a pressure of cm (about 147 × 10 6 Pa) to obtain a molded body having a diameter of 10 mm and a thickness of 5 mm. This molded body was sintered in vacuum at 1450 ° C. for 60 minutes to obtain a cermet alloy used for a nozzle for an injection molding machine.

2 to 5 are photographs of the structure of a cross section of a sintered body of this cermet alloy, taken by an electron microscope. The magnification of the structure photograph in each figure is 2400 times in FIG. 2 and 16000 in FIG.
4 times, 20,000 times in FIG. 4, and 75,000 times in FIG.

As shown in FIGS. 2 and 3, this cermet alloy is an extremely dense sintered body. Vickers hardness Hv is 2
It was 010.

Ti in the portions 1 to 8 shown in FIGS.
Table 5 shows the values of the contents of Co and W analyzed by an electron microscope with an energy dispersive X-front detector.

FIG. 6 shows the X-ray analysis result of the cermet alloy. From Table 5 and FIGS. 2 to 6, it was found that the composition of each phase of the cermet alloy used in the nozzle for the injection molding machine of this example was as follows. The TiC particles are a cored structure having a TiC core and a (Ti, W) (B, C) skin phase. Note that (Ti,
W) (B, C) has the same face-centered cubic structure as TiC, and the diffraction peaks of TiC and (Ti, W) (B, C) overlap in FIG. The W-Co-B compound partially contains the core of CoWB and CoW ₂ B ₂
It is a cored structure having a skin phase.

[0042]

[Table 5]

Example 3 A cermet alloy used in a nozzle for an injection molding machine was produced in the same manner as in Example 2 except that the formulations shown in Tables 6 and 7 were used, and the Vickers hardness and crack resistance were measured. The measurement results are shown in Tables 6 and 7 together with the composition of this cermet alloy.
Shown in. The unit of crack resistance (CR) is kg / mm.

[0044]

[Table 6]

[0045]

[Table 7]

From Tables 6 and 7, it is recognized that the cermet alloy used in the nozzle for the injection molding machine of this example has high hardness and toughness. Further, as the added WB increases, the Vickers hardness Hv increases, but the crack resistance CR decreases. As the amount of Co increases, the crack resistance C
R is slightly improved, but Vickers hardness is reduced. And, the Co / WB ratio is limited because when Co is too much compared with WB, the amount of Co remaining as metallic Co increases and the core structure of W—Co—B decreases, so that the crack resistance is improved. With respect to the ratio, the decrease in hardness is more remarkable, and the decrease in hardness is more severe than the improvement in toughness. Also, W
Metal C that does not react with WB when B is larger than Co
This is because o becomes too small and it becomes difficult to densify and sinter.

Example 4 A cermet alloy used in a nozzle for an injection molding machine was produced in the same manner as in Example 3 except that the compounding amounts shown in Table 8 were used, and Vickers hardness and crack resistance were measured. The measurement results are shown in Table 8 together with the compounding composition of this cermet alloy. As shown in Table 8, it shows high hardness and high toughness.

[0048]

[Table 8]

Example 5 The MC, MN, and MCN have a particle size of 0.5 to 10 μm.
m WC, TiC, TaC, NbC, TiN, TiCN
Using MoB and WB with a particle size of 1.0 to 5.0 μm
And 5 to 10 μm of Co and Ni were mixed according to the formulation (volume%) shown in Table 1. 1,500 kgf of these mixtures
/ Cm ² (about 147 × 10 Pa) was press-molded to obtain a molded body having a diameter of 10 mm and a height of 5 mm. This molded body is subjected to 1500 ° C, 1525 ° C and 1550 ° C, respectively
Was sintered for 1 hour to obtain a cermet alloy used for a nozzle for an injection molding machine. Table 9 shows Vickers hardnesses Hv (1500), Hv (1525) and Hv (1550) and crack resistance CR (150) corresponding to the above sintering temperatures.
The values of 0), CR (1525) and CR (1550) are also shown. Note that ICP-Co is the value of Co in the binder phase measured by plasma emission analysis. That is, the sintered body was crushed to 325 mesh or less to be used as a material for analysis, only the metal phase was selectively dissolved in the acid solution, and the undissolved powder was removed from the solution by filtration with a filter to remove Co in the solution. It is an analysis. Thereby, the amount of metallic Co remaining in the binder phase of the sintered body can be analyzed. In addition, No. 1 to 1 in the table
21 is an example of the cermet alloy used for the nozzle for the injection molding machine of the present invention.

[0050]

[Table 9]

The cermet alloys used in the nozzles for injection molding machines of the examples of the present invention all have Vickers hardness of 1
It can be seen that the crack resistance CR exceeds 800 and is large.

FIG. 7 is a view schematically showing the X-ray diffraction result of the sintered body in the example of the cermet alloy used in the nozzle for the injection molding machine of the present invention, and WC-30 vol% M
It is an example when the thing of oB-10vol% Co was sintered at 1500 degreeC. As is apparent from FIG. 10, most of Co reacts with MoB by sintering to form CoMo ₂ B ₂ and CoMoB which are Mo—Co—B compounds.

Next, No. 2 WC-5 vol% M in Table 9
The structure of a sintered body having a composition of oB-25vol% WB-10vol% Co and sintered at 1525 ° C. was observed using X-ray diffraction. The results are shown in FIG. 8. This sintered body has a WC phase, Co (Mo, W) ₂ B ₂ phase Co (Mo, W)
It was confirmed to have a multi-phase structure composed of B phase and Co phase.

In addition, TiC-15vo of No. 9 in Table 9
1% MoB-15 vol% WB-10 vol% Co having a compounding composition and sintered at 1525 ° C. The texture of the sintered body was X.
It was observed using line diffraction. As a result, this sintered body
C phase, {Ti, (Mo, W)} (B, C) phase, Co (M
It was confirmed to have a multi-phase structure composed of an o, W) ₂ B ₂ phase, a Co (Mo, W) B phase, and a Co phase. Moreover, regarding TiC, it was found that the TiC phase forms a core portion, and a so-called cored structure is formed in which the outer periphery is surrounded by {(Ti, (Mo, W)} (B, C) phase.

9 to 12 show No. 1 and No in Table 1.
2 shows a photograph of a metal microstructure of a sintered body having a composition of 2 and sintered at 1525 ° C. (2400 times that of No. 1 in FIG. 9).
FIG. 10 No. 1 16000 times, FIG. 11 No. 2 240
0 times, 16000 times that of No. 2 in FIG. 12). From the figure, it is understood that this alloy has a fine and dense structure.

The injection molding nozzles were actually manufactured by using the cermet alloys of Examples 1 to 5 used in the nozzle for the injection molding machine of the present invention, and the nozzles of this embodiment and the conventional nozzle (SKD61) were used. , Quenching H _R C50) was used to evaluate the wear resistance.

As a result, the injection molding machine nozzles of the examples of the present invention all showed extremely good wear resistance as compared with the conventional materials. This is because in the cermet alloy used for the injection molding machine nozzle of the invention of the present application, high hardness MC, MN and MCN are used as hard particles, and a part of low hardness Co after sintering is W-Co-. This is because a B compound and / or a Mo-Co-B compound is formed, and the bond strength between the W-Co-B phase and / or the Mo-Co-B phase and the Co phase is high.

Further, when the nozzle for injection molding machine of the embodiment of the present invention was used to investigate the corrosion resistance, a very good result was obtained. This is because in the ceramic alloy used in the nozzle for an injection molding machine of the present invention, a part of WB and / or MoB reacts with MC, MN and MCN, and M
(M, MN, and MCN particles) (M,
W) (B, C), (M, W) (B, N), (M, W)
(B, CN) composite phase and / or (M, Mo)
(B, C), (M, Mo) (B, N), (M, Mo)
Forming a complex phase of (B, CN), MC, MN and MCN
This is because the particles have a cored structure composed of a core portion and an outer skin portion, and the outer skin phase thereof is a phase containing W and / or Mo and B in a larger amount than that of the core portion and having extremely high corrosion resistance.

Further, as a result of performing a life test on the nozzle for injection molding machine of the embodiment of the present invention and the conventional nozzle, the life test of each nozzle of each embodiment has 3 to 5 times as long as that of the conventional nozzle. It was confirmed.

[0060]

As described above, according to the nozzle for the injection molding machine of the present invention, since the cermet alloy having high hardness, denseness and excellent toughness is used, it is cheaper than the nozzle for the conventional injection molding machine. Moreover, there is an excellent effect that a nozzle for an injection molding machine having excellent durability can be provided.

Further, the cermet alloy used in the nozzle for an injection molding machine of the present invention has an advantage that it can be sintered at a high density under reduced pressure or normal pressure sintering without using HIP or hot press.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing an X-ray diffraction result of a sintered body in Example 1 of the present invention.

FIG. 2 is an electron micrograph of a metal microstructure of a cermet alloy used in a nozzle for an injection molding machine according to an example of the present invention (magnification: 2400 times).

FIG. 3 is an electron micrograph of a metal microstructure of a cermet alloy used in a nozzle for an injection molding machine according to an example of the present invention (magnification: 16000 times).

FIG. 4 is a photograph of a metal microstructure of a cermet alloy used in a nozzle for an injection molding machine according to an example of the present invention, taken by an electron microscope (magnification: 26000 times).

FIG. 5 is an electron micrograph of a metal microstructure of a cermet alloy used in a nozzle for an injection molding machine according to an example of the present invention (magnification: 75,000 times).

FIG. 6 is an X-ray diffraction result of a cermet alloy used in a nozzle for an injection molding machine according to an example of the present invention.

FIG. 7 is a diagram schematically showing an X-ray diffraction result of a sintered body according to an example of the present invention.

FIG. 8 is a diagram schematically showing an X-ray diffraction result of another sintered body according to an example of the present invention.

FIG. 9 is a photograph of a metal microstructure of a cermet alloy used in a nozzle for an injection molding machine according to an example of the present invention, taken by an electron microscope (magnification: 2400 times).

FIG. 10 is an electron micrograph of a metal microstructure of a cermet alloy used in a nozzle for an injection molding machine according to an example of the present invention (magnification: 16000 times).

FIG. 11 is a photograph of a metal microstructure of a cermet alloy used in a nozzle for an injection molding machine according to an example of the present invention, taken by an electron microscope (magnification: 2400 times).

FIG. 12 is an electron micrograph of a metal microstructure of a cermet alloy used in a nozzle for an injection molding machine according to an example of the present invention (magnification: 16000 times).

FIG. 13 is a diagram showing a schematic configuration of a water jet cutting device.

Claims (19)

[Claims] 1. A MC, MN, and MCN of one or more kinds (M is one or more kinds of transition metal elements of Groups 4a, 5a, and 6a of the Periodic Table) and a W-Co-B compound. A nozzle for an injection molding machine, comprising a cermet alloy comprising a hard layer containing a main component and / or a hard layer containing a Mo-Co-B compound as a main component, and a binder phase containing Co as a main component. 2. The nozzle for an injection molding machine according to claim 1, wherein the binder phase metal Co is 7% by weight or less. 3. One or two of MC, MN, and MCN.
A hard phase mainly composed of at least one kind (M is one or more kinds of transition metal elements of groups 4a, 5a and 6a of the periodic table) and W-
Hard phase mainly composed of Co-B compound and / or Mo
A hard body mainly composed of a hard phase mainly composed of a —Co—B compound and a binder phase mainly composed of Co, wherein the hard phase mainly composed of one or more of MC, MN and MCN is
One or more of MC, MN and MCN, and (M, W) (B, C), (M, W) (B, N), (M,
W) one or more of (B, CN) and / or (M, Mo) (B, C), (M, Mo) (B, N),
A nozzle for an injection molding machine, which uses a cermet alloy composed of (M, Mo) (B, CN). 4. The hard phase mainly composed of one kind or two or more kinds of MC, MN and MCN is one of MC, MN and MCN.
Type or two or more types of cores, and (M, W) (B,
C), (M, W) (B, N) and (M, W) (B, C
N) one kind or two kinds or more and / or one kind of (M, Mo) (B, C), (M, Mo) (B, N) and (M, Mo) (B, CN). The nozzle for an injection molding machine according to claim 3, which is composed of two or more kinds of outer peripheral portions. 5. A hard phase composed mainly of one or more of MC, MN and MCN (M is one or more of transition metal elements of the periodic table 4a, 5a and 6a) and W. −
Hard phase mainly composed of Co-B compound and / or Mo
A sintered body comprising a hard phase containing a —Co—B compound as a main component and a binder phase containing a Co as a main component, and comprising W—Co—B
The hard phase mainly composed of compounds is CoWB and CoW ₂ B ₂
Consists, hard phase composed mainly of Mo-Co-B compound, a nozzle for an injection molding machine characterized by using a cermet alloy comprising CoMoB and CoMo ₂ B _2. 6. A hard phase mainly composed of a W—Co—B compound mainly comprises a cored structure consisting of a core part of CoW ₂ B ₂ and an outer peripheral part of CoWB, and mainly comprises a Mo—Co—B compound. The nozzle for an injection molding machine according to claim 5, wherein the hard phase to be formed is mainly a cored structure composed of a core portion of CoMo ₂ B ₂ and an outer peripheral portion of CoMoB. 7. A hard phase mainly composed of one or more of MC, MN and MCN (M is one or more of transition metal elements of groups 4a, 5a and 6a of the periodic table) and W. −
Hard phase mainly composed of Co-B compound and / or Mo
A hard body mainly composed of a hard phase mainly composed of a —Co—B compound and a binder phase mainly composed of Co, wherein the hard phase mainly composed of one or more of MC, MN and MCN is
One or more of MC, MN and MCN, and one of (M, W) (B, C), (M, W) (B, N) and (M, W) (B, CN) or 2 or more and /
Or (M, Mo) (B, C), (M, Mo) (B,
N) and (M, Mo) (made B, CN) 1 or more kinds of hard phase composed mainly of W-Co-B compound is, CoWB and _{CoW 2 B 2, Mo-Co} -B compound A hard phase mainly composed of a cermet alloy composed of CoMoB and CoMo ₂ B ₂ is used as a nozzle for an injection molding machine. 8. The hard phase mainly composed of one kind or two or more kinds of MC, MN and MCN is one of MC, MN and MCN.
Type or two or more types of cores, and (M, W) (B,
C), (M, W) (B, N) and (M, W) (B, C
One or more of N) and / or (M, Mo)
(B, C), (M, Mo) (B, N) and (M, Mo)
The nozzle for an injection molding machine according to claim 7, comprising one or more of (B, CN). 9. The hard phase mainly composed of a W—Co—B compound is mainly composed of a cored structure composed of a core part of CoW ₂ B ₂ and an outer peripheral part of CoWB, and mainly composed of a Mo—Co—B compound. The nozzle for an injection molding machine according to claim 7 or 8, wherein the hard phase to be formed is mainly a cored structure composed of a core portion of CoMo ₂ B ₂ and an outer peripheral portion of CoMoB. 10. A hard phase mainly composed of TiC and WC
Hard phase mainly composed of o-B compound and / or Mo-
A hard body mainly composed of a Co—B compound and a binder phase mainly composed of Co, wherein the hard phase mainly composed of TiC includes TiC and (Ti, W) (B, C) and A nozzle for an injection molding machine, characterized by using a cermet alloy composed of / or (Ti, Mo) (B, C). 11. A hard phase mainly composed of TiC is TiC.
11. The nozzle for an injection molding machine according to claim 10, wherein the nozzle comprises a core portion of (1) and an outer peripheral portion of (Ti, W) (B, C) and / or an outer peripheral portion of (Ti, Mo) (B, C). 12. A hard phase mainly composed of TiC and WC
Hard phase mainly composed of o-B compound and / or Mo-
Hard phase composed mainly of Co-B compound, and a sintered body made of a binder phase composed mainly of Co, hard phase composed mainly of W-Co-B compound is made CoWB and CoW ₂ B ₂ , A hard phase mainly composed of Mo-Co-B compound,
A nozzle for an injection molding machine, which is characterized by using a cermet alloy composed of CoMoB and CoMo ₂ B ₂ . 13. A hard phase mainly composed of a W—Co—B compound mainly comprises a cored structure consisting of a core part of CoW ₂ B ₂ and an outer peripheral part of CoWB, and mainly comprises a Mo—Co—B compound. The nozzle for an injection molding machine according to claim 12, wherein the hard phase is mainly composed of a cored structure composed of a core portion of CoMo ₂ B ₂ and an outer peripheral portion of CoMoB. 14. A hard phase mainly composed of TiC and WC
Hard phase mainly composed of o-B compound and / or Mo-
A hard body mainly composed of a Co—B compound and a binder phase mainly composed of Co, wherein the hard phase mainly composed of TiC includes TiC and (Ti, W) (B, C) and / Or (Ti, Mo) (B, C), WC
The hard phase mainly composed of the o-B compound is CoWB and Co.
W ₂ consists B _2, hard phase composed mainly of Mo-Co-B compound, a nozzle for an injection molding machine characterized by using a cermet alloy comprising CoMoB and CoMo ₂ B _2. 15. The hard phase mainly composed of TiC is TiC.
15. The nozzle for an injection molding machine according to claim 14, which comprises the core portion and the outer peripheral portion of (Ti, W) (B, C) and / or the outer peripheral portion of (Ti, Mo) (B, C). 16. A hard phase mainly composed of a W—Co—B compound is composed of a core part of CoW ₂ B ₂ and an outer peripheral part of CoWB, and a hard phase mainly composed of a Mo—Co—B compound is Co.
The nozzle for an injection molding machine according to claim 14 or 15, comprising a core portion of Mo ₂ B ₂ and an outer peripheral portion of CoMoB. 17. A WC and W—Co—B compound and / or
Alternatively, a nozzle for an injection molding machine, characterized by using a cermet alloy comprising a hard phase mainly composed of a Mo-Co-B compound and a binder phase mainly composed of Co. 18. The nozzle for an injection molding machine according to claim 17, wherein the binder phase metal Co is 3.5 wt% or less. 19. A hard phase mainly composed of a W—Co—B compound is composed of CoWB, or CoWB and CoW ₂ B ₂ , and a hard phase mainly composed of a Mo—Co—B compound is C.
The nozzle for an injection molding machine according to claim 17 or 18, which comprises oMoB or CoMoB and CoMo ₂ B ₂ .