JPH0679981B2 - Manufacturing method of low pore ZrB2 system sintered body - Google Patents
Manufacturing method of low pore ZrB2 system sintered bodyInfo
- Publication number
- JPH0679981B2 JPH0679981B2 JP63319404A JP31940488A JPH0679981B2 JP H0679981 B2 JPH0679981 B2 JP H0679981B2 JP 63319404 A JP63319404 A JP 63319404A JP 31940488 A JP31940488 A JP 31940488A JP H0679981 B2 JPH0679981 B2 JP H0679981B2
- Authority
- JP
- Japan
- Prior art keywords
- sintering
- sintered body
- zrb
- zrb2
- manufacturing
- 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.)
- Expired - Lifetime
Links
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、低気孔ZrB2系焼結体の製法に関する。The present invention relates to a method for producing a low-pore ZrB 2 system sintered body.
IVa,Va,VIa族金属硼化物は難焼結性のものが多く、焼結
密度の高いものが得難くポーラスとなり易い。常圧焼
結、ホットプレス焼結いずれにおいても焼結助剤が使用
されるが、得られた焼結体には数μｍ〜数十μｍの気孔
は常に多数存在している（ファインセラミックスVo1.5
108〜115（1984））。Many of the group IVa, Va, and VIa metal borides are difficult to sinter, and it is difficult to obtain those with a high sintering density, and they tend to be porous. A sintering aid is used in both normal pressure sintering and hot press sintering, but the obtained sintered body always has a large number of pores of several μm to several tens of μm (Fine Ceramics Vo1. Five
108-115 (1984)).
従来、この種の金属硼化物焼結体の高密度を図るため
に、焼結パターンを変えたり、原料粒度を調整すること
が提案されているが、十分に満足したものは得られてい
ない。Conventionally, in order to achieve a high density of this type of metal boride sintered body, it has been proposed to change the sintering pattern or adjust the grain size of the raw material, but a sufficiently satisfactory one has not been obtained.
焼結体に存在する気孔は機械的強度の低下だけでなく、
耐食性や電気伝導性に大きく影響を与える。従来技術で
は、上記のように、焼結体中に必ず数μｍ〜数十μｍの
気孔が数多く存在している。本発明は、原材料の選定と
焼結条件、プロセスの適正化により、粗大気孔をなく
し、著しく緻密なZrB2系焼結体を得ることを目的とする
ものである。The pores present in the sintered body not only decrease the mechanical strength,
It greatly affects corrosion resistance and electrical conductivity. In the prior art, as described above, a large number of pores of several μm to several tens of μm always exist in the sintered body. An object of the present invention is to eliminate coarse air holes and obtain a remarkably dense ZrB 2 system sintered body by selecting raw materials, sintering conditions, and optimizing the process.
〔課題を解決するための手段〕 すなわち、本発明は、ZrB2100重量部に対し、CrとＣの
両方、Cr3C2、WC及びMoCの４種から選ばれた１種以上１
〜30重量部を配合してなる混合原料を常圧焼結またはホ
ットプレス焼結して焼結体の気孔径を平均10μｍ以下と
した後さらにHIP焼結を行うことを特徴とする低気孔ZrB
2系焼結体の製法である。[Means for Solving the Problems] That is, the present invention relates to 100 parts by weight of ZrB 2 and at least one selected from four kinds of both Cr and C, Cr 3 C 2 , WC and MoC.
Low porosity ZrB characterized by performing atmospheric pressure sintering or hot press sintering of a mixed raw material containing up to 30 parts by weight to make the pore size of the sintered body 10 μm or less on average and further performing HIP sintering.
This is a method for manufacturing a 2 type sintered body.
以下、さらに詳しく本発明について説明する。The present invention will be described in more detail below.
本発明で使用される混合原料は、主原料のZrB2粉末と焼
結助剤の混合物であり、その焼結助剤としては、CrとＣ
の両方、Cr3C2、WC及びMoCの４種から選ばれた１種以上
である。両者の割合は、ZrB2100重量部に対し焼結助剤
１〜30重量部好ましくは５〜20重量部である。焼結助剤
が１重量部未満では焼結体の気孔を低減させる効果は小
さく、また30重量部をこえるとZrB2の割合が少なくなっ
てZrB2の本来の特性が損なわれる。ZrB2粉末の平均粒度
は５μｍ以下好ましくは２μｍ以下であり、焼結助剤の
それもZrB2粉末と同程度でよいがより細かい粒度が好ま
しい。ZrB2粉末と焼結助剤の混合は通常のボールミルに
よる乾式または湿式で行われる。The mixed raw material used in the present invention is a mixture of ZrB 2 powder as a main raw material and a sintering aid, and as the sintering aid, Cr and C are used.
, And one or more selected from four kinds of Cr 3 C 2 , WC and MoC. The ratio of both is 1 to 30 parts by weight, preferably 5 to 20 parts by weight, of the sintering aid with respect to 100 parts by weight of ZrB 2 . If the amount of the sintering aid is less than 1 part by weight, the effect of reducing the pores of the sintered body is small, and if it exceeds 30 parts by weight, the proportion of ZrB 2 decreases and the original characteristics of ZrB 2 are impaired. The average particle size of the ZrB 2 powder is 5 μm or less, preferably 2 μm or less, and that of the sintering aid may be similar to that of the ZrB 2 powder, but a finer particle size is preferable. The mixing of the ZrB 2 powder and the sintering aid is performed by a dry method or a wet method using an ordinary ball mill.
焼成は常圧焼結あるいはホットプレス（HP）焼結を行な
った後HIP焼結を行う。常圧焼結、HP焼結の焼成温度は1
800〜2200℃、焼成時間は30分〜６時間程度で、雰囲気
は真空中又はアルゴン、ヘリウム、一酸化炭素などの非
酸化性とする。HP焼結における加圧力は100〜300kg/cm2
程度である。For firing, HIP sintering is performed after performing atmospheric pressure sintering or hot press (HP) sintering. Normal pressure sintering, HP sintering temperature is 1
The temperature is 800 to 2200 ° C., the firing time is about 30 minutes to 6 hours, and the atmosphere is vacuum or non-oxidizing such as argon, helium and carbon monoxide. Pressure in HP sintering 100~300kg / cm 2
It is a degree.
以上の条件で常圧焼結あるいはHP焼結した後に焼結体の
表面組織をSEM等で観察すると、平均気孔径が10μｍ以
下であることが確認できる。この焼結段階において焼結
体の平均気孔径が10μｍ以上であるとHIP焼結による気
孔の閉塞効果即ち焼結体の密度の増大効果は見られな
い。HIP焼結の条件としては、Ar,N2等の不活性ガス中で
1800〜2200℃,30分〜６時間程度で、数100kg/cm2〜数10
00kg/cm2の加圧下で行う。When the surface structure of the sintered body is observed by SEM or the like after pressureless sintering or HP sintering under the above conditions, it can be confirmed that the average pore diameter is 10 μm or less. If the average pore diameter of the sintered body is 10 μm or more in this sintering stage, the effect of HIP sintering to close the pores, that is, the effect of increasing the density of the sintered body is not observed. The conditions for HIP sintering are as follows in an inert gas such as Ar and N 2.
1800 to 2200 ℃, 30 minutes to 6 hours, several 100kg / cm 2 to several 10
It is performed under a pressure of 00 kg / cm 2 .
最終的に気孔径が最大１μｍ以下の緻密な焼結体を得る
には焼結するまえのグリーン成形体の密度ムラを少なく
することが重要なことであり、そのためには、成形体
は、通常、金型プレスあるいはCIP成形で作製するが、
原料粉は出来るだけ流動性の良いものとし、ブリッジン
グ等粗大気孔発生の原因を除去する。流動性のよい原料
粉を得るには、スプレードライ法により造粒粉とすると
か、少量の水分添加を行う等公知の方法を採用すること
ができる。In order to finally obtain a dense sintered body having a maximum pore diameter of 1 μm or less, it is important to reduce the density unevenness of the green molded body before sintering. It is made by die press or CIP molding,
The raw material powder should be as fluid as possible to eliminate the causes of coarse air holes such as bridging. In order to obtain a raw material powder having good fluidity, a known method such as granulating powder by a spray drying method or adding a small amount of water can be adopted.
以下、実施例と比較例をあげてさらに具体的に本発明を
説明する。Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples.
実施例１ 純度98％以上のZrB2粉末とCr3C2粉末をボールミルで乾
式混合したものを金型プレス（100kg/cm2）した後（６
×４×150mm）CIP（冷間静水圧プレス、2.7ton/cm2、３
分間）成型し、真空雰囲気下（10-1mmHg）において表−
１に示す所定の温度、時間で焼成した。Example 1 ZrB 2 powder having a purity of 98% or more and Cr 3 C 2 powder were dry-mixed with a ball mill, and then the mixture was pressed with a mold (100 kg / cm 2 ) (6
× 4 × 150mm) CIP (cold isostatic press, 2.7ton / cm 2 , 3
Min.) And molded under vacuum atmosphere (10 -1 mmHg).
It was fired at a predetermined temperature and time shown in 1.
さらに、上記常圧焼結体をHIP（熱間静水圧プレス、1.8
ton/cm2×1900℃×3hr）焼結を行った。Furthermore, HIP (hot isostatic press, 1.8
(ton / cm 2 × 1900 ° C × 3 hr) sintering was performed.
得られた焼結体をダイヤモンドホイールで研削後、ラッ
ピングを行ない鏡面とした。このテストピースについて
SEM観察を行ない、気孔の存在状態を観察した。その結
果を表−１に示す。The obtained sintered body was ground with a diamond wheel and then lapped to obtain a mirror surface. About this test piece
SEM observation was performed to observe the existence state of pores. The results are shown in Table-1.
表−１に示された結果から、常圧焼結またはHP焼結によ
り気孔径が平均10μｍ以下のものについてはHIP焼結に
より気孔径が１μｍ以下の非常に緻密な焼結体が得られ
ることが判った。 From the results shown in Table-1, it is possible to obtain a very dense sintered body with a pore size of 1 μm or less by HIP sintering if the average pore size is 10 μm or less by normal pressure sintering or HP sintering. I understood.
本発明によれば、粗大気孔のほとんどない最大粒径１μ
ｍ以下の緻密な組織をもったZrB2系焼結体を得ることが
できる。According to the present invention, the maximum particle size of 1μ with few coarse air holes
It is possible to obtain a ZrB 2 system sintered body having a dense structure of m or less.
第１図は、実験No.5において、常圧焼結後HIP焼結して
得られた焼結体の、第２図は、同じく実験No.5において
常圧焼結しただけの焼結体の粒子構造を示す倍率1000の
SEM写真である。Fig. 1 shows a sintered body obtained by HIP sintering after atmospheric pressure sintering in Experiment No. 5, and Fig. 2 shows a sintered body just under atmospheric pressure sintering in Experiment No. 5. 1000 times magnification showing the grain structure of
It is a SEM photograph.
Claims (1)
C2、WC及びMoCの４種から選ばれた１種以上１〜30重量
部を配合してなる混合原料を常圧焼結またはホットプレ
ス焼結して焼結体の気孔径を平均10μｍ以下とした後さ
らにHIP焼結を行うことを特徴とする低気孔ZrB2焼結体
の製法。1. To 100 parts by weight of ZrB 2 , both Cr and C, Cr 3
A mixed raw material prepared by mixing 1 to 30 parts by weight of one or more kinds selected from four kinds of C 2 , WC and MoC is subjected to pressureless sintering or hot press sintering and the average pore diameter of the sintered body is 10 μm or less. After that, HIP sintering is further performed, and the method for producing a low-pore ZrB 2 sintered body.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63319404A JPH0679981B2 (en) | 1988-12-20 | 1988-12-20 | Manufacturing method of low pore ZrB2 system sintered body |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63319404A JPH0679981B2 (en) | 1988-12-20 | 1988-12-20 | Manufacturing method of low pore ZrB2 system sintered body |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02164776A JPH02164776A (en) | 1990-06-25 |
| JPH0679981B2 true JPH0679981B2 (en) | 1994-10-12 |
Family
ID=18109808
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63319404A Expired - Lifetime JPH0679981B2 (en) | 1988-12-20 | 1988-12-20 | Manufacturing method of low pore ZrB2 system sintered body |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0679981B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5093993B2 (en) * | 2005-04-06 | 2012-12-12 | 学校法人東海大学 | Ceramic sintered body |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6355165A (en) * | 1986-08-26 | 1988-03-09 | 旭硝子株式会社 | Tib2 base sintering material and manufacture |
| JPH0627036B2 (en) * | 1988-06-22 | 1994-04-13 | 日本鋼管株式会社 | High strength and high toughness TiB ▲ Bottom 2 ▼ Ceramics |
-
1988
- 1988-12-20 JP JP63319404A patent/JPH0679981B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH02164776A (en) | 1990-06-25 |
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