JPH0427186B2 - - Google Patents
Info
- Publication number
- JPH0427186B2 JPH0427186B2 JP62031268A JP3126887A JPH0427186B2 JP H0427186 B2 JPH0427186 B2 JP H0427186B2 JP 62031268 A JP62031268 A JP 62031268A JP 3126887 A JP3126887 A JP 3126887A JP H0427186 B2 JPH0427186 B2 JP H0427186B2
- Authority
- JP
- Japan
- Prior art keywords
- powder
- sintering
- sintered body
- hfb
- zrb
- 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
- 229910052751 metal Inorganic materials 0.000 claims description 21
- 239000002184 metal Substances 0.000 claims description 21
- 239000000843 powder Substances 0.000 claims description 20
- 238000005245 sintering Methods 0.000 claims description 18
- 239000011812 mixed powder Substances 0.000 claims description 10
- 229910007946 ZrB Inorganic materials 0.000 claims description 6
- 229910052735 hafnium Inorganic materials 0.000 claims description 6
- 238000002156 mixing Methods 0.000 claims description 6
- 239000000203 mixture Substances 0.000 claims description 6
- 229910052726 zirconium Inorganic materials 0.000 claims description 6
- 239000000919 ceramic Substances 0.000 claims description 5
- 238000004519 manufacturing process Methods 0.000 claims description 5
- 229910010055 TiB Inorganic materials 0.000 claims description 4
- 229910052719 titanium Inorganic materials 0.000 claims description 4
- 238000000034 method Methods 0.000 description 17
- 238000002844 melting Methods 0.000 description 9
- 230000007797 corrosion Effects 0.000 description 8
- 238000005260 corrosion Methods 0.000 description 8
- 230000008018 melting Effects 0.000 description 8
- 239000002994 raw material Substances 0.000 description 6
- 150000002739 metals Chemical class 0.000 description 5
- 239000000126 substance Substances 0.000 description 5
- 150000001875 compounds Chemical class 0.000 description 4
- 239000013078 crystal Substances 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- 230000006866 deterioration Effects 0.000 description 2
- 239000007791 liquid phase Substances 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 229910003862 HfB2 Inorganic materials 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 239000012300 argon atmosphere Substances 0.000 description 1
- 239000012298 atmosphere Substances 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- 238000001513 hot isostatic pressing Methods 0.000 description 1
- 238000007731 hot pressing Methods 0.000 description 1
- 230000002706 hydrostatic effect Effects 0.000 description 1
- 238000009766 low-temperature sintering Methods 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 238000007613 slurry method Methods 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
Landscapes
- Ceramic Products (AREA)
Description
〈産業上の利用分野〉
本発明は、低温での普通焼結でも、耐食性に優
れた二硼化金属系セラミツクスを得ることが出来
る方法に関するものである。
〈従来の技術〉
二硼化金属、特にTiB2，ZrB2，HfB2は、溶融
金属に対する耐食性に優れている為に、溶融金属
用容器、溶融金属接触型のセンサー部材あるいは
溶融金属用電極等多くの用途に用いられている。
しかし乍ら、これらの二硼化金属の殆どがその
融点は約3000℃と高く、難焼結性であり、高密度
焼結を得る為には、例えば特公昭54−43966号公
報で示される様に1000気圧もの高圧下焼結法を採
用したり、又は例えば特公昭58−3997号公報で示
される様な低融点物質を添加する焼結法を採用し
なければならず、設備の大型化に伴う製法上の難
点があつたり、又は異種低融点物質を加える事で
得られる焼結体の組成が変化し、その結果二硼化
金属が本来有する優れた特性が損なわれる、更に
は焼結体中に上記低融点物質がそのまゝの形態で
残留し、この残留部に溶融金属が接触し、そこか
ら腐食が生起するという様な問題があつた。
〈発明が解決しようとする問題点〉
本発明は、上記高圧下焼結法の製法上の難点あ
るいは得られる製品の寸法上の制約（大形状物は
得難い）や、異種低融点物質添加法の製品特性の
低下という問題を解決し、低温焼結で高密度焼結
体が得られ、しかも該焼結体中にその特性を低下
せしめる要因となる他の物質を含まない様な方法
を提供することを目的とする。
〈問題点を解決する為の手段〉
本発明の上記目的は、下記の如き手段を採用す
る事で達成出来る。
即ち、焼結後の焼結体の組成に、Ｂ原子を65〜
67原子％含有する様に、TiB2，ZrB2，HfB2粉末
の中の少なくとも１種以上とTi，Zr，Hf，ZrB，
HfB粉末の中の少なくとも１種以上とを混合し、
該混合粉末を焼結することを特徴とする二硼化金
属系セラミツクスの製造方法である。
以下本発明につき詳述する。
二硼化金属は、そのＢの含有率が65〜67原子％
の範囲で六方晶系の結晶構造を有する。即ちＢの
含有率は、ある幅を持ち化学量論量から多少離れ
た範囲でも六方晶系を示し、その耐食性や電気伝
導性を失う事はないのである。従つてそれ単独で
は焼結性が悪いTiB2，ZrB2，HfB2粉末の１種以
上の混合粉末に対し、低融点の金属あるいは化合
物であるTi，Zr，Hf，TiB，ZrB，HfB粉末の
一種以上を、全混合粉末に組成を、上述した如く
Ｂの含有量が、65〜67原子％となる様な量に調整
するか、更にＢ粉末を加えＢの含有量が65〜67原
子％となるように調整する。又は最初からTi，
Zr，Hf，TiB，ZrB，HfB粉末の一種以上とＢ
粉末とを同じくＢが65〜67原子％となる様な量に
調整混合し、その後焼結を行えば、これら混合粉
末中に含まれる低融点金属あるいは化合物が溶融
し、液相焼結状態となり低温で容易に焼結が行
え、焼結完了時には全てがＢが65〜67原子％の範
囲にある二硼化金属となるものである。
本発明方法による焼結は、原料として用いる粉
末の酸化を防ぐ為に、非酸化性雰囲気であること
が好ましく、又用いる原料粉末の粒度は出来る限
り微細である方がよく、通常4μm以下の平均粒
径、より好ましくは1μm以下の平均粒径の粉末と
する。これらの原料粉末中のＢの含有量は、厳格
に規制すべきであり、上述した如くＢ量が65〜67
原子％の範囲を外れると得られる焼結体の全てを
六万晶系となす事が出来ないことは勿論、その量
が57原子％よりも多ければ得られる焼結体の緻密
化が困難となり、一方65原子％よりも少なければ
焼結体中に金属や一硼化物等が残存し耐食性や耐
酸化性を低下させる様になるのである。
次に本発明の代表的な方法について述べる。
即ち、まず所定の混合比に混合した粉末組成物
を金型に充填し、0.5〜10ton／cm2程度のプレス圧
で冷間圧縮し、得られる圧粉体をラバープレスに
より0.5〜10ton／cm2程度の静水圧を加え均一な圧
力分布を持つ圧粉成形体となすが、又はボールミ
ル等でスラリー化した後、差圧を利用したり加圧
したりして成形する泥漿法により圧粉体となし、
該圧粉体を真空中若しくはアルゴン中で1800〜
2600℃の条件下で30〜200分間焼結する方法があ
る。
又別の方法としては、ホツトプレス法や熱間静
水圧法もあり、いずれの方法を採用しても容易に
十分緻密な焼結体が得られる。
〈実施例〉
次に実施例を示し本発明方法を更に詳述する。
この実施例は、HfB2粉末98.4重量％とZr粉末
1.6重量％とを十分に混合し、2ton／cm2で金型成
形した後も、4ton／cm2でラバープレスして圧粉成
形体を得、該圧粉成形体をアルゴン雰囲気中で
2400℃下に90分間加熱焼成した。この様にして得
られた焼結体の空隙率は非常に小さく、抗折力は
25Kg／mm2であつた。この焼結体の表面層を研削除
去し、750℃の溶融アルミニウム中に24時間浸漬
し耐食性を調べた結果、形状、質量ともに全く変
化が見られず1.6重量％Zr−残HfB2焼結体が優れ
た耐食性を有している事が確認された。この1.6
重量％Zr−残HfB2焼結体の例をNo.１とし、他に
それぞれに組成を変えた原料混合粉末から上記実
施例の場合と同様の条件で製造した焼結の特性等
を下記第１表に示す。但し第１表中No.34は比較例
である。
<Industrial Application Field> The present invention relates to a method for obtaining metal diboride ceramics with excellent corrosion resistance even by normal sintering at low temperatures. <Prior art> Metal diboride, especially TiB 2 , ZrB 2 , and HfB 2 , has excellent corrosion resistance against molten metal and is therefore used in containers for molten metal, sensor members that contact molten metal, electrodes for molten metal, etc. Used for many purposes. However, most of these metal diborides have a high melting point of approximately 3000°C and are difficult to sinter. For example, it is necessary to adopt a sintering method under high pressure of 1,000 atmospheres, or a sintering method in which a low melting point substance is added, as shown in Japanese Patent Publication No. 58-3997, which increases the size of the equipment. However, the composition of the sintered body may change due to the addition of different low melting point substances, resulting in loss of the excellent properties of metal diboride, and furthermore, the sintering process may be difficult. There was a problem in that the low melting point substance remained in the same form in the body, and molten metal came into contact with this residual portion, causing corrosion therefrom. <Problems to be Solved by the Invention> The present invention solves the above-mentioned difficulties in the manufacturing process of the high-pressure sintering method, limitations in the dimensions of the resulting product (large-sized products are difficult to obtain), and the method of adding different low-melting substances. To provide a method that solves the problem of deterioration of product properties, obtains a high-density sintered body by low-temperature sintering, and does not contain other substances that cause deterioration of the properties. The purpose is to <Means for solving the problems> The above object of the present invention can be achieved by adopting the following means. That is, 65 to 65 B atoms are added to the composition of the sintered body after sintering.
At least one of TiB 2 , ZrB 2 , HfB 2 powder and Ti, Zr, Hf, ZrB,
Mixing with at least one kind of HfB powder,
This is a method for producing metal diboride ceramics, which comprises sintering the mixed powder. The present invention will be explained in detail below. Metal diboride has a B content of 65 to 67 at%
It has a hexagonal crystal structure in the range of . In other words, the content of B has a certain range and exhibits a hexagonal system even if it deviates somewhat from the stoichiometric amount, without losing its corrosion resistance or electrical conductivity. Therefore, compared to a mixed powder of one or more of TiB 2 , ZrB 2 , and HfB 2 powders, which have poor sinterability when used alone, Ti, Zr, Hf, TiB, ZrB, and HfB powders, which are metals or compounds with low melting points, are used. Either adjust the composition of one or more types to the entire mixed powder so that the B content is 65 to 67 at% as described above, or add B powder so that the B content is 65 to 67 at%. Adjust so that Or Ti from the beginning,
One or more of Zr, Hf, TiB, ZrB, HfB powder and B
By adjusting the amount of B to 65 to 67 atomic% and then sintering it, the low melting point metals or compounds contained in these mixed powders will melt and form a liquid phase sintered state. Sintering can be easily carried out at low temperatures, and upon completion of sintering, all metal diborides contain B in the range of 65 to 67 atomic percent. Sintering according to the method of the present invention is preferably performed in a non-oxidizing atmosphere in order to prevent oxidation of the powder used as a raw material, and the particle size of the raw material powder used is preferably as fine as possible, usually with an average of 4 μm or less. The powder has a particle size, more preferably an average particle size of 1 μm or less. The content of B in these raw material powders should be strictly regulated, and as mentioned above, the B content should be 65 to 67.
Of course, if the amount is outside the range of 57 atomic percent, it will not be possible to make all of the sintered body 60,000 crystal system, and if the amount exceeds 57 atomic percent, it will be difficult to make the sintered body dense. On the other hand, if it is less than 65 atomic %, metals, monoborides, etc. will remain in the sintered body, reducing corrosion resistance and oxidation resistance. Next, a typical method of the present invention will be described. That is, first, a powder composition mixed at a predetermined mixing ratio is filled into a mold, cold compressed with a press pressure of about 0.5 to 10 ton/cm 2 , and the resulting green compact is compressed with a rubber press at a pressure of 0.5 to 10 ton/cm 2 . A powder compact with a uniform pressure distribution is formed by applying hydrostatic pressure of about 2 degrees, or a compact is formed by a slurry method in which it is made into a slurry using a ball mill, etc., and then formed using differential pressure or pressurization. none,
The green compact is heated to 1800~
There is a method of sintering at 2600°C for 30 to 200 minutes. Other methods include a hot pressing method and a hot isostatic pressing method, and a sufficiently dense sintered body can be easily obtained by using either method. <Examples> Next, examples will be shown to further explain the method of the present invention in detail. This example contains 98.4 wt% HfB2 powder and Zr powder
After thoroughly mixing with 1.6% by weight and molding at 2 ton/cm 2 , rubber pressing was performed at 4 ton/cm 2 to obtain a green compact, and the green compact was molded in an argon atmosphere.
It was baked at 2400°C for 90 minutes. The porosity of the sintered body obtained in this way is extremely small, and the transverse rupture strength is
It was 25Kg/ mm2 . The surface layer of this sintered body was removed by grinding, and the corrosion resistance was examined by immersing it in molten aluminum at 750°C for 24 hours. As a result, no change was observed in both shape and mass, resulting in a 1.6 wt% Zr-residual HfB 2 sintered body. It was confirmed that it has excellent corrosion resistance. This 1.6
The example of the weight% Zr-residual HfB 2 sintered body is taken as No. 1, and the characteristics of sintered products manufactured from other raw material mixed powders with different compositions under the same conditions as in the above example are shown below. It is shown in Table 1. However, No. 34 in Table 1 is a comparative example.
【表】【table】
【表】
〈発明の効果〉
以上述べて来た如く、本発明方法によれば原料
混合粉末中に含有せしめる低融点の金属、化合物
の為に低い温度で液相焼結がなされる為に低温の
しかも通常の焼結法で十分緻密な焼結体を得る事
が出来、かつ原料混合粉末中のＢの量を、65〜67
原子％の範囲としているが為に焼結後は低融点金
属や化合物が残存する事なく全てが六万晶系を持
つ二硼化金属となる為に得られる焼結体は優れた
耐食性を示すのである。[Table] <Effects of the Invention> As stated above, according to the method of the present invention, liquid phase sintering is performed at a low temperature due to the low melting point metals and compounds contained in the raw material mixed powder. Moreover, it is possible to obtain a sufficiently dense sintered body using the normal sintering method, and the amount of B in the raw material mixed powder can be reduced to 65 to 67.
Although it is in the atomic percent range, after sintering, no low melting point metals or compounds remain and all metal diboride has a 60,000-crystal system, so the obtained sintered body exhibits excellent corrosion resistance. It is.
Claims (1)
子％含有する様に、TiB2，ZrB2，HfB2粉末の中
の少なくとも１種以上とTi，Zr，Hf，ZrB，
HrB粉末の中の少なくとも１種以上とを混合し、
該混合粉末を焼結することを特徴とする二硼化金
属系セラミツクスの製造方法。 ２ 焼結後の焼結体の組成に、Ｂ原子を65〜67原
子％含有する様に、TiB2，ZrB2，HfB2粉末の少
なくとも１種以上にTi，Zr，Hf，TiB，ZrB，
HfB粉末の中の少なくとも１種以上とＢ粉末と
を混合し、該混合粉末を焼結することを特徴とす
る二硼化金属系セラミツクスの製造方法。 ３ 焼結後の焼結体の組成に、Ｂ原子を65〜67原
子％含有する様に、Ti，Zr，Hf，TiB，ZrB，
HfB粉末の中の少なくとも１種以上とＢ粉末と
を混合し、該混合粉末を焼結することを特徴とす
る二硼化金属系セラミツクスの製造方法。[Scope of Claims] 1. At least one of TiB 2 , ZrB 2 , and HfB 2 powder and Ti, so that the composition of the sintered body contains 65 to 67 at % of B atoms. Zr, Hf, ZrB,
Mixing with at least one kind of HrB powder,
A method for producing metal diboride ceramics, which comprises sintering the mixed powder. 2. Ti , Zr, Hf , TiB , ZrB,
A method for producing metal diboride ceramics, comprising mixing at least one type of HfB powder and B powder, and sintering the mixed powder. 3. Ti, Zr, Hf, TiB, ZrB,
A method for producing metal diboride ceramics, comprising mixing at least one type of HfB powder and B powder, and sintering the mixed powder.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62031268A JPS63201067A (en) | 1987-02-13 | 1987-02-13 | Manufacture of metal diboride base ceramics |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62031268A JPS63201067A (en) | 1987-02-13 | 1987-02-13 | Manufacture of metal diboride base ceramics |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63201067A JPS63201067A (en) | 1988-08-19 |
| JPH0427186B2 true JPH0427186B2 (en) | 1992-05-11 |
Family
ID=12326589
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62031268A Granted JPS63201067A (en) | 1987-02-13 | 1987-02-13 | Manufacture of metal diboride base ceramics |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63201067A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH06667B2 (en) * | 1988-11-04 | 1994-01-05 | 工業技術院長 | Boride-aluminum nitride ceramic materials |
| JP4834188B1 (en) * | 2011-05-27 | 2011-12-14 | 有志 米田 | Impact generator |
-
1987
- 1987-02-13 JP JP62031268A patent/JPS63201067A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS63201067A (en) | 1988-08-19 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EXPY | Cancellation because of completion of term |