White metal

Japanese: ホワイトメタル（英語表記）white metal

Although it is often mistaken for a white alloy due to its meaning, this is a part of the white alloys, which are bearing alloys mainly made of low melting point metals such as lead, tin (Sn), antimony (Sb), and zinc. Among these, Sn-Sb-Cu alloys containing 70% or more tin (for example, 90Sn-6Sb-4Cu) were invented by American I. Babbitt around 1850 and are called Babbitt metals. They have the best castability and bearing performance. However, because tin is expensive, varieties have been developed in which some of the tin is replaced with lead or other metals (for example, 6Sn-10Sb-84Pb). The reason why white metals are good for bearing alloys is that the hard β-phase SnSb is scattered in the soft eutectic phase to support the rotating shaft, and the eutectic phase is depressed to form an oil reservoir and improve lubrication. When copper (Cu) is added, compounds such as Cu ₂ Sb and Cu ₆ Sn ₅ are formed, which work in the same way as SnSb. In addition to copper, nickel, sodium, calcium, barium, etc. are also added.

Source: Encyclopaedia Britannica Concise Encyclopedia About Encyclopaedia Britannica Concise Encyclopedia Information

Japanese:

語義から白色合金と誤られやすいが，これは白色合金の一部で，鉛，スズ Sn，アンチモン Sb，亜鉛などの低融点金属を主体とする軸受合金である。このうちスズを 70%以上含む Sn-Sb-Cu系合金 (たとえば 90Sn-6Sb-4Cu) は 1850年頃アメリカの I.バビットの発明でバビットメタルといわれ，鋳造性，軸受性能とも最もすぐれている。しかしスズが高価なので一部を鉛その他で置き換えた品種が開発された (たとえば 6Sn-10Sb-84Pb) 。ホワイトメタルが軸受合金によい理由は，硬いβ相 SnSbが軟らかい共晶地に散在して回転軸を支え，共晶地がくぼんで油だまりになって潤滑をよくするからで，銅 Cu加調の場合は Cu₂Sb ，Cu₆Sn₅ などの化合物ができ SnSbと同様に働く。銅のほかニッケル，ナトリウム，カルシウム，バリウムなどが添加されるものもある。

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