JPH0466265A - Method for removing residual stress in fiber-reinforced metal - Google Patents
Method for removing residual stress in fiber-reinforced metalInfo
- Publication number
- JPH0466265A JPH0466265A JP17979990A JP17979990A JPH0466265A JP H0466265 A JPH0466265 A JP H0466265A JP 17979990 A JP17979990 A JP 17979990A JP 17979990 A JP17979990 A JP 17979990A JP H0466265 A JPH0466265 A JP H0466265A
- Authority
- JP
- Japan
- Prior art keywords
- fiber
- residual stress
- reinforced metal
- metal
- temp
- 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.)
- Pending
Links
- 229910052751 metal Inorganic materials 0.000 title claims abstract description 28
- 239000002184 metal Substances 0.000 title claims abstract description 28
- 238000000034 method Methods 0.000 title claims abstract description 8
- 239000007788 liquid Substances 0.000 claims abstract description 20
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims abstract description 14
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 7
- 238000005058 metal casting Methods 0.000 claims abstract description 6
- 239000012783 reinforcing fiber Substances 0.000 claims abstract description 6
- 239000000463 material Substances 0.000 claims description 13
- 238000005242 forging Methods 0.000 claims description 6
- 238000010791 quenching Methods 0.000 claims 1
- 230000000171 quenching effect Effects 0.000 claims 1
- 229920000049 Carbon (fiber) Polymers 0.000 abstract description 8
- 239000004917 carbon fiber Substances 0.000 abstract description 8
- 238000005266 casting Methods 0.000 abstract description 7
- 239000000835 fiber Substances 0.000 abstract description 7
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 abstract description 6
- 238000001816 cooling Methods 0.000 abstract description 4
- 230000007547 defect Effects 0.000 abstract description 3
- 238000007598 dipping method Methods 0.000 abstract 2
- 238000004519 manufacturing process Methods 0.000 abstract 1
- 229910052782 aluminium Inorganic materials 0.000 description 8
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 8
- 238000005336 cracking Methods 0.000 description 3
- 239000011156 metal matrix composite Substances 0.000 description 3
- 150000002739 metals Chemical class 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 239000002131 composite material Substances 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 239000010953 base metal Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000003733 fiber-reinforced composite Substances 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 230000002787 reinforcement Effects 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
本発明は、繊維強化金属の残留応力除去方法に係り、特
に液体窒素等の超低温液体を利用することにより簡単か
つ経済的に引張残留応力を除去することができ、繊維強
化金属の割れ等の欠陥を防止できるようにした残留応力
の除去方法に関する。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for removing residual stress in fiber-reinforced metals, and particularly for removing tensile residual stress easily and economically by using an ultra-low temperature liquid such as liquid nitrogen. The present invention relates to a method for removing residual stress that can prevent defects such as cracks in fiber-reinforced metal.
従来の技術
従来、繊維強化金属(FRM)の−例として、炭素繊維
強化金属基複合材料は、非常に細いフィラメント状の炭
素繊維を極めて密に一方向に引き揃え、母材の一例たる
アルミニウム中に埋設し、溶湯鍛造(高圧鋳造)して成
形するが、高温の状態から常温まで冷却する際、両材料
の熱膨張係数の違いから、アルミニウムが収縮すること
ができず、引張残留応力が生じ、その結果この複合材料
は使用中に割れを生じ易いという欠陥があった。Conventional technology Conventionally, carbon fiber reinforced metal matrix composite materials, as an example of fiber reinforced metal (FRM), are made by arranging very thin filament-like carbon fibers extremely densely in one direction, and forming carbon fibers in aluminum, which is an example of a base material. Aluminum is buried in aluminum and formed by molten metal forging (high-pressure casting), but when cooling from a high temperature state to room temperature, due to the difference in the coefficient of thermal expansion of the two materials, the aluminum cannot contract, resulting in tensile residual stress. As a result, this composite material had the drawback of being susceptible to cracking during use.
即ち、アルミニウム鋳物の熱膨張係数α、は2IXIO
−6/’Cであるのに対し、炭素繊維の熱膨張係数α、
は−0,IXI O−6/ ’C乃至一〇、 4XI
O−’/lであり、熱の変化によってほとんどその長さ
が変化しないか又は温度上昇と共にわずかに縮み、温度
の下降と共にわずかに伸びる傾向があるため、アルミニ
ウムは高温の状態から冷却されると、大幅に縮もうとす
るが、炭素繊維はその長さが変わらないか又は逆にわず
かに縮もうとするため、アルミニウムはその収縮作用を
炭素繊維によって妨害されることになり、この結果繊維
強化金属には残留引張応力が生ずることになるのである
。That is, the coefficient of thermal expansion α of aluminum casting is 2IXIO
-6/'C, whereas the thermal expansion coefficient α of carbon fiber is
is -0, IXI O-6/ 'C to 10, 4XI
O-'/l, and its length tends to change little with changes in heat, or to shrink slightly as the temperature rises, and to stretch slightly as the temperature falls, so when aluminum is cooled from a high temperature state, it , the carbon fiber tends to shrink significantly, but the length of the carbon fiber does not change or, on the contrary, it tries to shrink slightly, so the shrinkage action of the aluminum is blocked by the carbon fiber, and as a result, the fiber reinforcement Residual tensile stress will be generated in the metal.
しかし従来この残留応力を除去する技術はなく、この種
の繊維強化金属の割れ易いという欠点は全く解消されて
いないのか現状である。However, there is no conventional technology for removing this residual stress, and the drawback of this type of fiber-reinforced metals, such as their tendency to break, remains unresolved at present.
目 的
本発明は、上記した従来技術の欠点を除くためになされ
たものであって、その目的とするところは、強化繊維を
一方向に引き揃えて金属中に埋設して溶湯鋳造(高圧鍛
造)して成形され常温まで冷却されて引張残留応力を有
する繊維強化金属を、液体窒素等の超低温液体中に投入
して急冷した後該超低温液体から取り出して常温に放置
して昇温させることにより圧縮残留応力を住じさせて引
張残留応力と相殺させることよって残留する引張応力を
完全に除去することであり、またこれによって特に炭素
繊維強化金属基複合材料の割れに対する強度を増大させ
ることである。Purpose The present invention has been made in order to eliminate the drawbacks of the above-mentioned prior art, and its purpose is to align reinforcing fibers in one direction and embed them in metal to perform molten metal casting (high pressure forging). ), a fiber-reinforced metal that has been molded and cooled to room temperature and has tensile residual stress is put into an ultra-low temperature liquid such as liquid nitrogen, rapidly cooled, and then taken out of the ultra-low temperature liquid and left at room temperature to rise in temperature. The purpose is to completely eliminate residual tensile stress by allowing compressive residual stress to settle and offset with tensile residual stress, and thereby to increase the cracking strength of carbon fiber-reinforced metal matrix composite materials in particular. .
構成
要するに本発明は、強化繊維を一方向に引き揃えて金属
中に埋設して溶湯鋳造(高圧鍛造)して成形され常温ま
で冷却されて引張残留応力を有する繊維強化金属を、液
体窒素等の超低温液体中に投入して急冷した後該超低温
液体から取り出して常温に放置して昇温させることによ
り圧縮残留応力を生じさせて前記引張残留応力と相殺さ
せることを特徴とするものである。Structure In short, the present invention is a fiber-reinforced metal that is formed by molten metal casting (high-pressure forging) by aligning reinforcing fibers in one direction, embedding them in metal, and having tensile residual stress after being cooled to room temperature. It is characterized in that it is put into an ultra-low temperature liquid, rapidly cooled, and then taken out from the ultra-low temperature liquid and left to stand at room temperature to raise the temperature, thereby generating a compressive residual stress that offsets the tensile residual stress.
一般に、繊維強化複合材料における母材(アルミニウム
鋳物等)に生ずる残留歪みε、は、繊維のヤング率をE
f、繊維の体積率゛をVf、母材の熱膨張係数をα1、
繊維の熱膨張係数をα1、温度差をΔT、複合材料のヤ
ング率をECとすると、8m =E、V、(a、−ex
、)ΔT/Ecで表わされる。In general, residual strain ε, which occurs in the base material (aluminum casting, etc.) in fiber reinforced composite materials, increases the Young's modulus of the fibers E
f, the volume fraction of the fiber is Vf, the thermal expansion coefficient of the base material is α1,
If the coefficient of thermal expansion of the fiber is α1, the temperature difference is ΔT, and the Young's modulus of the composite material is EC, then 8m = E, V, (a, -ex
, ) is expressed as ΔT/Ec.
従って、高圧鋳造凝固されて常温まで冷却されて引張残
留応力が生じている繊維強化金属に対し、高圧鋳造凝固
と逆の処理をすれば、−旦冷却′された後の昇温の際に
今度は圧縮残留応力が発生するため、この圧縮残留応力
と引張残留応力とが相殺され、有害な引張残留応力は除
去されるとの着眼を得て本発明に至ったものである。Therefore, if a fiber-reinforced metal that has been solidified by high-pressure casting, cooled to room temperature, and has tensile residual stress, is subjected to the reverse process of high-pressure casting and solidification, it will be The present invention was developed based on the idea that since compressive residual stress is generated, the compressive residual stress and the tensile residual stress cancel each other out, and the harmful tensile residual stress is removed.
そこで本発明では、強化繊維を一方向に引き揃えて金属
中に埋設して溶湯鋳造(高圧鍛造)して成形され常温ま
で冷却されて引張残留応力を有する繊維強化金属を、液
体窒素等の超低温液体中に投入して急冷した後該超低温
液体から取り出して常温に放置して昇温させることによ
り圧縮残留応力を生じさせて引張残留応力と相殺させる
のである。Therefore, in the present invention, reinforcing fibers are aligned in one direction, embedded in metal, molded by molten metal casting (high-pressure forging), and cooled to room temperature to create a fiber-reinforced metal that has tensile residual stress. After being put into a liquid and rapidly cooled, it is taken out from the ultra-low temperature liquid and left to stand at room temperature to raise the temperature, thereby generating compressive residual stress that offsets the tensile residual stress.
液体窒素は、約−195℃の超低温液体であるから、常
温の繊維強化金属がこれに投入されて冷却される際、非
常に急速に冷却されるため、母材の金属は完全に収縮す
る時間がなく、凍結してしまい、このときの収縮による
引張残留応力の増加はほとんどないと考えられる。Liquid nitrogen is an ultra-low temperature liquid with a temperature of approximately -195°C, so when fiber-reinforced metal at room temperature is put into it and cooled down, it is cooled very rapidly, so it takes time for the base metal to completely shrink. It is thought that there is no increase in tensile residual stress due to shrinkage at this time.
しかし超低温液体から繊維強化金属を取り出して常温に
放置すると、母材は次第に温度上昇して(放置)伸びよ
うとするが、この場合も繊維がこれを妨害して母材の伸
長を許さない、このため母材内には圧縮残留応力が生じ
、この圧縮残留応力と前の引張残留応力とが互いに相殺
し、いずれの残留応力も除去される。However, when a fiber-reinforced metal is removed from an ultra-low temperature liquid and left at room temperature, the base material gradually rises in temperature and attempts to elongate (if left unattended), but in this case too, the fibers block this and do not allow the base material to elongate. Therefore, a compressive residual stress is generated in the base material, and this compressive residual stress and the previous tensile residual stress cancel each other out, and both residual stresses are removed.
作用
本発明は、上記のように構成されており、以下その作用
について説明する。本発明の方法により製造された繊維
強化金属は、その母材に残留応力を有していないため、
特に引張荷重により早期に割れを生ずることがなく、十
分な強度を有するものであり、従来のこの種の繊維強化
金属の欠点を見事に解決し得たものである。Function The present invention is constructed as described above, and its function will be explained below. Since the fiber-reinforced metal produced by the method of the present invention has no residual stress in its base material,
In particular, it does not crack early due to tensile loads, has sufficient strength, and successfully solves the drawbacks of conventional fiber-reinforced metals of this type.
効果
本発明は、上記のように強化繊維を一方向に引き揃えて
金属中に埋設して溶湯鋳造(高圧鍛造)して成形され常
温まで冷却されて引張残留応力を有する繊維強化金属を
、液体窒素等の超低温液体中に投入して急冷した後該超
低温液体から取り出して常温に放置して昇温させること
により圧縮残留応力を生じさせて引張残留応力と相殺さ
せるようにしたので、残留する引張応力を完全に除去す
ることができ、またこの結果特に炭素繊維強化金属基複
合材料の割れに対する強度を増大させることができる効
果がある。Effects As described above, the present invention is made by arranging reinforcing fibers in one direction, embedding them in metal, molding them by molten metal casting (high-pressure forging), cooling them to room temperature, and making the fiber-reinforced metal with tensile residual stress into a liquid. After being put into an ultra-low temperature liquid such as nitrogen, rapidly cooled, and then taken out from the ultra-low temperature liquid and left at room temperature to raise the temperature, compressive residual stress is generated and offset with the tensile residual stress, so the residual tensile stress is Stress can be completely removed, and as a result, the strength against cracking of the carbon fiber-reinforced metal matrix composite material can be particularly increased.
特許出願人 日野自動車工業株式会社Patent applicant: Hino Motors Co., Ltd.
Claims (1)
鋳造(高圧鍛造)して成形され常温まで冷却されて引張
残留応力を有する繊維強化金属を、液体窒素等の超低温
液体中に投入して急冷した後該超低温液体から取り出し
て常温に放置して昇温させることにより圧縮残留応力を
生じさせて前記引張残留応力と相殺させることを特徴と
する繊維強化金属の残留応力除去方法。The reinforcing fibers are aligned in one direction, embedded in the metal, molded by molten metal casting (high-pressure forging), cooled to room temperature, and has tensile residual stress.The fiber-reinforced metal is then placed into an ultra-low temperature liquid such as liquid nitrogen. A method for removing residual stress in a fiber-reinforced metal, the method comprising: quenching the material, then removing it from the ultra-low temperature liquid, leaving it at room temperature and raising the temperature to generate compressive residual stress to offset the tensile residual stress.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP17979990A JPH0466265A (en) | 1990-07-07 | 1990-07-07 | Method for removing residual stress in fiber-reinforced metal |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP17979990A JPH0466265A (en) | 1990-07-07 | 1990-07-07 | Method for removing residual stress in fiber-reinforced metal |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH0466265A true JPH0466265A (en) | 1992-03-02 |
Family
ID=16072099
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP17979990A Pending JPH0466265A (en) | 1990-07-07 | 1990-07-07 | Method for removing residual stress in fiber-reinforced metal |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH0466265A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005325485A (en) * | 2004-05-17 | 2005-11-24 | Tokai Univ | Fiber-reinforced composite material |
CN101887472A (en) * | 2009-05-12 | 2010-11-17 | 通用汽车环球科技运作公司 | The method of unrelieved stress and distortion in the prediction quenching aluminium casting |
-
1990
- 1990-07-07 JP JP17979990A patent/JPH0466265A/en active Pending
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005325485A (en) * | 2004-05-17 | 2005-11-24 | Tokai Univ | Fiber-reinforced composite material |
JP4585230B2 (en) * | 2004-05-17 | 2010-11-24 | 学校法人東海大学 | Fiber reinforced composite material |
CN101887472A (en) * | 2009-05-12 | 2010-11-17 | 通用汽车环球科技运作公司 | The method of unrelieved stress and distortion in the prediction quenching aluminium casting |
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