| On the one hand, wear caused by friction is one of the main reasons of failure of machines and equipments. On the other hand, processes of friction result in loss of power and waste of energy. Lubricants play a significant role to reduce friction and wear. However, traditional lubricants act only on the retardation of wear and tear limitedly but have no wear-self-repairing function, that is to say, can not produce negative wear.According to a tentative idea of zero-wear, two kinds of lubricating additives EDT and EDTM with an excellent function of wear-self-repairing during friction processes were developed in this dissertation. Properties of the two kinds of new additives developed, such as effect of wear-self-repairing, load carrying effect, anti-friction effect, inhibition of elevated temperature of lubricating oil and cooperativity with commercial oils, were investigated in this dissertation. Furthermore, their extreme loading capacity (PB value) and anti-wear effect were also investigated systematically by four-ball test.The achievements of this dissertation were manifested in several aspects as follows:1. The additive EDT had excellent wear-self-repairing properties.1) The EDT had excellent wear-self-repairing properties. In the whole test period, i.e. in 450 minutes, the wear of both moving and static pieces of the rubbing pair lubricated by the oil with the addition of the EDT kept negative values. The surfaces of the rubbing pair were always covered wear-self-repairing films. The films yielded rapidly. So the wear was always limited in the films.2) The oil with the addition of the EDT had excellent bearing capacity. Its minimum PB value was 1372N, which was 4.667 times as high as that of the base oil and 2.333 times of the oil in which the additive T202 was added.3) The EDT had excellent anti-friction effect. The friction coefficient of steel-steel rubbing pairs lubricated by the oil with the addition of the EDT equaled 0.0092-0.0121, which reduced by 64.5%~87.9% as compared with that of the T202. The higher the load was, the more evident its effect of anti-friction was. Similarly, its effect of anti-friction had a positive relationship to the testing duration.4) The EDT had excellent inhibition of elevated temperature of lubricating oil. When oils tested were lubricating steel-steel rubbing pairs under the load of 490N, the elevated temperature of oil with the addition of the EDT was 20 ℃, which was 87℃ lower than that of the T202. Its inhibition of elevated temperature of lubricating oil increased obviously with climbing of the load.5) The excellent wear-self- repairing property of the EDT appeared good suitability for load. In a wide loading range of 294N to 882N during friction and wear tests the oil with the addition of the EDT showed its good effect of wear-self-repairing, good anti-friction effect and good inhibition of elevated temperature of lubricating oil. The EDT leaded steel-steel rubbing pairs to negative wear, low friction coefficient kept under 0.0121 and small elevated temperature of lubricating oil within 35℃. By contrast, the wear and friction of steel-steel rubbing pairs lubricated by the oil with the addition of the traditional extreme press additive T202 as well as the temperature of the oil steep rose under the load reaching 490N. At that time, the temperature of the oil reached 130℃ and the rubbing pairs lost normal working capacity yet.2. The additives EDT and EDTM could make four kinds of commercial lubricating oils tested to have excellent wear-self-repairing and anti-friction effects. A positive wear of steel-steel rubbing pairs and relative high friction coefficient equaling 0.016 and 0.0172 respectively appeared when the rubbing pairs were lubricated by the turbine oil N46 and the gear oil N220 respectively, while a positive wear and relative low friction coefficient equaling 0.0072~0.010, which fell by 41.9%~59.1% as compared with the two formers, when by N46 and N220 in which the EDT and EDTM were added respectively. Furthermore, a serious scuffing and relative high friction coefficient over 0.1 appeared when the rubbing pairs were lubricated by the hydraulic oil N46 and mechanical oil N68, while a positive wear and relative low friction coefficient equaling 0.0070-0.0080, which fell by more than 92% as compared with the two formers, when by N46 and N68 in which the EDT and EDTM were added respectively.3. Tribological performances of additives EDT and EDTM were investigated with a four-ball tester under twelve testing conditions combined with 4 levels of loading (196,294, 392 and 490N) and 3 testing periods (10, 30 and 60min.) respectively. Test results demonstrated that the higher the load was and the longer the test continued, the more obvious the effect of the EDT and EDTM upon anti-wear and anti-friction was. The addition of EDT into base oil could make both wear and friction of four-ball rubbing pairs decreased obviously: the diameter of worn scars on the balls decreased from 0.328mm~1.22mm to 0.289mm~0.445mm, that is to say, the wear of four-ball rubbing pairs lubricated by the oil with the addition of the EDT reduced by 11.9%~63.5% as compared with that by the base oil; and the friction coefficient fell from 0.0962-0.1026 to 0.0646-0.0748, that is to say, the friction under the condition of lubrication of the oil with the addition of the EDT decreased by 20.0%~37.1% as compared with that of the base oil. Similarly, the addition of EDTM into base oil could also make both wear and friction of four-ball rubbing pairs decreased obviously: the diameter of worn scars on the balls decreased to 0.287mm~0.393mm, that is to say, the wear of four-ball rubbing pairs lubricated by the oil with the addition of the EDTM reduced by 12.5%~67.8% as compared with that by the base oil; and the friction coefficient fell to 0.0179-0.0369, that is to say, the friction under the condition of lubrication of the oil with the addition of the EDTM decreased by 62.9%~80.0% as compared with that of the base oil. After the additives EDT and EDTM were added into four kinds of commercial lubricating oils, their extreme loading capacity, i.e. PB value, increased from 470.4N~548.8N to 646.8N-1450.4N, friction coefficient decreased by 15.0%~59.1% (except N220-EDT) and relative wear resistance increased by 32%-106%.4. The cooperativity of the additive EDT with 6 kinds of commercial additives most in use was investigated systematically. The following regularity was indicated:1) The EDT could cooperate with additives T304, T306, T321, T106, T152 and agent M in the field of anti-friction effectively, with additives T304, T152 and agent M in the field of anti-wear and with additive T304 in the field of increase of load carrying capacity efficaciously.2) The cooperativity of the additive EDT with the 6 kinds of commercial additives most in use was related not only to the sorts of additives but also to the compound proportion and the added amount in oils. There was little probability of that the effects of anti-friction, anti-wear and increase of load carrying capacity were synchronized with the compounding process.The excellent properties, such as wear-self-repairing effect, anti-friction effect, inhibition of elevated temperature of lubricating oil and suitability for load in a wide loading range, of...
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