【発明の詳細な説明】[Detailed description of the invention]
本発明は高強度、高導電性を有し、かつ半田付
け性及び耐疲労特性の優れた電線用銅合金に関す
るものである。
一般に航空機用電線、自動車用電線、その他電
気、電子機器用電線等、主に信号伝送を目的とし
て使用される電線には、高強度、高導電性、高半
田付け性及び高疲労特性が要求され、従来はCu
−1.0wt％（以下wt％を単に％と略記）Cd合金が
用いられていたが、この合金は人体に有害なCd
を含むため、良好な特性を有するも国内での製造
は中止されている。
最近Cu−1.0％Cd合金に代わるものとして、Cu
−0.5％Zr−0.7％Cr合金が用いられているが、こ
の合金は酵素との親和力の大きいZrを含むとこ
ろから、製造時に大気中で溶解するとZrが酸化
し、健全な鋳塊を得ることが難しい。またこの合
金は熱処理合金であるため製造工程が複雑とな
り、コスト高となる欠点があつた。更にこの合金
は半田付け性に劣るものであつた。
このため航空機用電線、自動車用電線、その他
電気、電子機器用電線として、Cu−1.0％Cd合金
やCu−0.5％Zr−0.7％Cr合金と同等の特性を有
し、かつ製造コストの安い合金が要求されてい
る。
本発明はこれに鑑み種々研究の結果、高強度、
高導電性を有し、かつ半田付け性及び耐疲労特性
が優れ、しかも熱処理等の特別な処理を必要とせ
ず、安価に製造することができる高強度、高導電
性電線用銅合金を開発したもので、Sn0.05〜1.0
％、Cr0.03〜0.2％、P0.01〜0.2％を含み、残部
Cuからなることを特徴とするものである。
即ち本発明は、CuにSn、Cr及びＰを添加し
て、これ等３元素を共存させることにより、Cu
特有の高導電性及び半田付け性を劣化させること
なく、強度及び耐疲労性を向上せしめたものであ
る。またCu−Cr合金は熱処理合金として知られ
ており、所望の特性を得るためには焼入れ、時効
処理が行なわれるが、本発明合金は、Sn、Cr及
びＰを共存させることにより加工硬化により所望
の強度が得られるものである。
しかして本発明合金の成分組成を上記の如く限
定したのは次の理由によるものである。
CuにSn、Cr及びＰを添加してこれ等３元素を
共存させることによりCu特有の高導電性及び半
田付け性を劣化させることなく、強度及び耐疲労
性を向上し得るも、Sn含有量が0.05％未満でも、
Cr含有量が0.03％未満でも強度及び耐疲労性の向
上効果が少なく、またSn含有量が1.0％を越えて
も、Cr含有量が0.2％を越えても、Ｐ含有量が0.2
％を越えても強度は向上し得るも、耐疲労性の向
上効果は飽和し、かつ合金の導電率及び半田付け
性を著しく低下させるためである。特にＰが多く
なると導電率の低下が著しく、その含有量が0.2
％以下であれば効果が認められも、望ましくは
0.01〜0.1％の範囲が良い。
本発明合金は上記の如く特別の熱処理を必要と
せず、例えば鋳塊を熱間圧延により荒引線とし、
これに中間焼鈍（温度400〜700℃、保持時間0.5
〜５時間）と冷間伸線を繰返して所望のサイズに
仕上げ、加工硬化により所望の強度を得ることが
できるものである。
次に本発明合金を実施例について詳細に説明す
る。
黒鉛ルツボを使用してCuを溶解し、その湯面
を木炭で覆い、Ｐ、Sn、Crを順次添加した後、
金型に鋳造して第１表に示す成分組成の巾25mm、
厚さ25mm、長さ300mmの鋳塊を得た。この鋳塊を
一面あたり2.5mm面削した後、溝ロールを用いて
熱間圧延し、直径８mmの荒引線とし、これに中間
焼鈍（温度500℃、保持時間１時間）と冷間伸線
を繰返し加えて直線0.8mmの線材とした。尚この
ときの最終加工率を60％とした。
これ等線材について引張強さ、導電率、半田付
け性及び耐疲労特性を測定した。その結果を第１
表に示す従来合金と比較して第２表に示した。
尚半田付け性は、直径0.8mmの線材より長さ50
mmの試片を５個切り出し、アセトン脱脂後フラツ
クスにロジンを用いて230℃の温度に保持した半
田浴（６％Sn−40％Pb）に挿入し、レスカ社ソ
ルダーチエツカーで最大ぬれ荷動を測定した。従
つてこの値が大きいほど半田付け性は良好であ
り、従来合金No.13と比較し、ほぼ同等のものを△
印、それ以下のものを×印、より優れているもの
を○印で表わした。
また耐疲労性は、直径0.8mmの線材より長さ１
ｍの試片を５個切り出し、中村式疲労試験機によ
り、荷重10〜25Kg／cm2の範囲内で試験して、Ｓ−
Ｎ曲線を作成し、この曲線が従来合金No.13とほぼ
同等のものを○印、幾分劣るものを△印、著しく
劣るものを×印で表わした。
The present invention relates to a copper alloy for electric wires that has high strength, high conductivity, and excellent solderability and fatigue resistance. In general, wires used primarily for signal transmission, such as aircraft wires, automobile wires, and wires for other electrical and electronic devices, are required to have high strength, high conductivity, high solderability, and high fatigue properties. , conventionally Cu
-1.0wt% (hereinafter wt% is simply abbreviated as %) Cd alloy was used, but this alloy contains Cd which is harmful to the human body.
Although it has good properties, domestic production has been discontinued. Recently, as an alternative to Cu-1.0%Cd alloy, Cu
-0.5% Zr - 0.7% Cr alloy is used, but since this alloy contains Zr, which has a high affinity with enzymes, if it is dissolved in the atmosphere during manufacturing, Zr will oxidize, resulting in a healthy ingot. is difficult. Furthermore, since this alloy is a heat-treated alloy, the manufacturing process is complicated and the cost is high. Furthermore, this alloy had poor solderability. For this reason, the alloy has properties equivalent to Cu-1.0%Cd alloy and Cu-0.5%Zr-0.7%Cr alloy, and is inexpensive to manufacture, as wire for aircraft, automobiles, and other electrical and electronic devices. is required. In view of this, the present invention has been developed as a result of various researches.
We have developed a high-strength, high-conductivity copper alloy for electric wires that has high conductivity, excellent solderability and fatigue resistance, and can be manufactured at low cost without the need for special treatments such as heat treatment. Sn0.05~1.0
%, including Cr0.03~0.2%, P0.01~0.2%, the balance
It is characterized by being made of Cu. That is, in the present invention, by adding Sn, Cr, and P to Cu and making these three elements coexist, Cu
It has improved strength and fatigue resistance without deteriorating its unique high conductivity and solderability. Further, Cu-Cr alloy is known as a heat-treated alloy, and is subjected to quenching and aging treatment in order to obtain the desired properties. However, the alloy of the present invention achieves the desired properties by work hardening by coexisting Sn, Cr, and P. strength can be obtained. The reason why the composition of the alloy of the present invention is limited as described above is as follows. By adding Sn, Cr, and P to Cu and making these three elements coexist, strength and fatigue resistance can be improved without deteriorating the high conductivity and solderability characteristic of Cu, but the Sn content Even if it is less than 0.05%,
Even if the Cr content is less than 0.03%, the effect of improving strength and fatigue resistance is small, and even if the Sn content exceeds 1.0% or the Cr content exceeds 0.2%, the P content is 0.2%.
%, the strength may be improved, but the effect of improving fatigue resistance is saturated and the electrical conductivity and solderability of the alloy are significantly reduced. In particular, when P increases, the conductivity decreases significantly, and the content is 0.2
Although the effect is recognized if it is less than %, it is preferable that
A range of 0.01 to 0.1% is good. The alloy of the present invention does not require any special heat treatment as described above; for example, the ingot is hot rolled to form a rough wire,
This is followed by intermediate annealing (temperature 400 to 700℃, holding time 0.5
It is possible to finish the wire into the desired size by repeating cold wire drawing (~5 hours) and obtain the desired strength by work hardening. Next, the alloy of the present invention will be described in detail with reference to Examples. After melting Cu using a graphite crucible, covering the hot water surface with charcoal, and sequentially adding P, Sn, and Cr,
Cast into a mold and have a width of 25 mm with the composition shown in Table 1,
An ingot with a thickness of 25 mm and a length of 300 mm was obtained. After face-cutting this ingot by 2.5 mm per side, it was hot rolled using grooved rolls to form a rough drawn wire with a diameter of 8 mm, which was then subjected to intermediate annealing (temperature 500℃, holding time 1 hour) and cold wire drawing. The addition was repeated to make a straight 0.8 mm wire. The final processing rate at this time was 60%. The tensile strength, electrical conductivity, solderability, and fatigue resistance properties of these wire rods were measured. The result is the first
Table 2 shows a comparison with the conventional alloy shown in the table. In addition, solderability is determined by using a wire with a diameter of 50 mm.
After degreasing with acetone and inserting into a solder bath (6%Sn-40%Pb) kept at 230℃ using rosin as a flux, we cut out 5 specimens with a diameter of 5 mm. was measured. Therefore, the larger this value is, the better the solderability is.Comparing with conventional alloy No. 13, it is found that almost the same alloy is △
Those with a lower score are marked with an x mark, and those with a better score are marked with an ○ mark. In addition, the fatigue resistance is higher than the wire rod with a diameter of 0.8 mm.
Cut out 5 specimens with a diameter of 1.5 m and test them using a Nakamura fatigue tester under a load of 10 to 25 kg/cm 2 to obtain an S-
An N curve was created, and those whose curves were approximately equivalent to conventional alloy No. 13 were marked with ○, those which were somewhat inferior were marked with △, and those which were significantly inferior were marked with ×.
【表】【table】
【表】【table】
【表】
第１表及び第２表から明らかなように、本発明
合金No.１〜No.５は引張強さ、導電率、半田付け性
及び疲労特性が良好で、従来合金であるCu−Cd
合金（No.13）と比較し、性能は幾分劣るも公害の
恐れがなく、従来合金であるCu−Zr−Cr合金
（No.12）と比較し、引張強さ、導電率、疲労特性
はほぼ同等で、半田付け性ははるかに優れてお
り、しかも特別の熱処理を必要としないため、安
価に提供することができるものであり、従来合金
No.12、No.13に充分代替できることが判る。
これに対し、本発明合金の組成範囲より外れる
比較合金は引張強さ、導電率、半田付け性及び疲
労特性の内、何れか一つ以上の特性が劣化してい
ることが判る。即ちSn含有量の少ない比較合金
No.６、Cr含有量の少ない比較合金No.８及びＰを
含まない比較合金No.11では、引張強さと疲労特性
が劣り、Sn含有量の多い比較合金No.７、Cr含有
量の多い比較合金No.９及びＰ含有量の多い比較合
金No.10では導電率及び半田付け性が劣つている。
このように本発明によれば、特別の熱処理を必
要とせず、引張強さ、導電率、半田付け性及び疲
労特性がバランスよく優れたもので、従来のCu
−Zr−Cr合金に充分代替できるものであり、航
空機用電線、自動車用電線、その他電気、電子機
器用電線として代替し得る顕著な効果を奏するも
のである。[Table] As is clear from Tables 1 and 2, alloys No. 1 to No. 5 of the present invention have good tensile strength, electrical conductivity, solderability, and fatigue properties, and the conventional alloy Cu-No. Cd
Compared to alloy (No. 13), the performance is somewhat inferior, but there is no risk of pollution, and compared to the conventional alloy Cu-Zr-Cr alloy (No. 12), it has better tensile strength, electrical conductivity, and fatigue properties. is almost the same, has much better solderability, and does not require special heat treatment, so it can be provided at a lower price than conventional alloys.
It can be seen that it can be sufficiently substituted for No. 12 and No. 13. On the other hand, it can be seen that the comparative alloys that fall outside the composition range of the alloy of the present invention have deteriorated in one or more of the tensile strength, electrical conductivity, solderability, and fatigue properties. That is, comparative alloys with low Sn content
Comparative alloy No. 6, comparative alloy No. 8 with a low Cr content, and comparative alloy No. 11 without P are inferior in tensile strength and fatigue properties, while comparative alloy No. 7, with a high Sn content, has a high Cr content. Comparative alloy No. 9 and comparative alloy No. 10 with a high P content have poor electrical conductivity and solderability. As described above, the present invention does not require special heat treatment and has excellent tensile strength, electrical conductivity, solderability, and fatigue properties in a well-balanced manner.
It can be used as a sufficient substitute for the -Zr-Cr alloy, and has a remarkable effect that it can be used as a substitute for aircraft wires, automobile wires, and other electrical and electronic equipment wires.