高力アルミニウム合金展伸材の摩耗について
1972 年 22 巻 4 号 p. 259-268
詳細
1972 年 22 巻 4 号 p. 259-268
In the previous papers, the authors described the wear and frictional properties of some typical aluminum alloy castings such as Lautal (AC2A-F), Lo-Ex (AC8A-T6), Y-alloy (AC5A-T6), and Al-Si alloys, and reported that these alloys had high wear resistance when combined with carbon steel and cast iron. In this paper, the wear of high strength wrought aluminum alloys, Al-5.3% Cu alloy and Al-4.1% Zn-1.5%Mg alloy, of which hardnesses had been varied by heat-treatments, was examined in the combination with carbon steel and cast iron.
The results obtained were summarized as follows:
(1) At a comparatively high sliding speed, seizure easily appeared on wrought aluminum alloys. The seizure appeared at a speed of about 1.5m/sec when rubbed with carbon steel, but it did not appear up to about 4m/sec when rubbed with cast iron, because graphite contained in cast iron acted as solid lubricant inhibiting intermetallic contact between sliding surfaces.
(2) At a low sliding speed of no appearance of seizure, dark layers containing iron or its oxide and/or aluminum oxide were formed on the sliding surface of aluminum alloys to prevent it from intermetallic contact. Therefore, the wear rates of both aluminum alloys and carbon steels or cast iron were very low.
(3) The heat treatment of wrough aluminum alloys was considered to have little effects on resistances to seizure and wear.
(4) Al-Zn-Mg alloy was superior to Al-Cu alloys in wear resistance under mild wear condition, but inferior in seizure resistance.
(5) The seizure appeared slightly more often in wrought aluminum alloys than in the aluminum alloy castings examined in the previous reports. The above facts would be explained by the phenomena that a greater amount of intermetallic compounds and hard pro-eutectic and/or eutectic silicon crystals were present in these alloy castings.
(6) In the combination of aluminum alloys with carbon steels and cast iron, the mechanical wear of steel and cast iron was restrained. The wear resistance of steel and cast iron was greatly improved by rubbing with aluminum alloys at a sliding speed of lower than 0.5m/sec for steels and at 12m/sec for cast iron.
