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10^mmHg程度の真空中において,Ni,Cu,Auの3種類の純金属により,同種金属同士の摩擦,摩耗の実験を行なった.実験はピン/円板型の試験機を用い,室温,一定荷重のもとで何段階かのすべり速度について行ない,速度特性に重点をおいた.ここで得られたおもな結果は以下のとおりである.(1)Ni,Cuの場合には,摩擦を開始してから数mのあいだ,摩擦係数μは低い値を示しているが,その後急に上昇し,以後すべり距離が増すに伴ってやや減少する傾向を示す.一方,Auの場合には,摩擦開始直後からμは高い値を示し,その後は摩擦が進むにつれてNi,Cuと同様の減少を示した.(2)CuとAuの場合には,摩擦係数は,すべり速度に関係なくほぼ一定であるが,Niについてはすべり速度の大きい領域で摩擦係数は高くなっている.(3)Ni,Cu,Auのいずれにおいても,あるすべり進度まではすべり速度が増すにつれて摩耗量は減少し,その後すべり速度の増加に伴い摩耗量は増大する.この境界となる速度は金属により異なる.この特性はAuについても顕著に見られるので,酸累の化学吸着による潤滑効果では説明できないようである.(4)すべり速度が増すにつれて摩擦面の荒れははげしくなり,発生する摩耗粉の粒子は大粒となってくるが,摩擦面のかたさはすべり速度には無関係である., Experiments have been carried out on friction and wear characteristics of Ni/Ni (Ni sliding on Ni), Cu/Cu and Au/Au in vacuum of 10^ Torr. A pin-and-disk machine has been used and tests have been conducted at room temperature, with the constant load of 262 grams and sliding velocities varied from 21 to 335 millimeter per second. The results obtained are as follows. (1) In the cases of Ni/Ni and Cu/Cu, coefficient of friction, μ, is low during the first several meters of sliding, which is followed by an abrupt rise in μ; after that the value of μ decreases very slowly, still maintaining high value. In the case of Au/Au, high value of μ is obtained from the outset of sliding, but the gradual decrease is observed also in the same way as the above cases. (2) The average value of μ for Cu/Cu and Au/Au is constant irrespective of the sliding velocity; that for Ni/Ni, however, seems to be higher in the high velocity range. (3) Wear rate first decreases as the sliding velocity increases. After arriving at some minimum value at a certain velocity, which varies with metal combinations, it increases with the increase of the slidng velocity. Since similar characteristics are observed also in the case of Au/Au, they may not always be accounted for by the lubricating effect of adsorbed oxygen layer. (4) With the increase in the sliding velocity, the wear scar is progressively roughened, and the wear debris increases in size. On the other hand, no change is observed in the hardness of wear scar with the change in sliding velocity., 資料番号: SA0125306000