In simple case the tribologic system from two materials may be presented by following scheme M1//M2, where the symbol is denotes the “third body” without liquid lubricant. If the friction velocity V and the specific loading P are fixed, the tribologic characteristics of the M1 surface are dependent on composition and properties of the counter-body, i.e. M2. And what are the true M1 properties?
Let’s assume that some friction condition (P, V, stationary regime, identity materials) are the “standard”. Then the sets of (fio,I lin,i o) values, which were received in corresponding systems Mi//Mi, may be presented as a “conventionality values” of the anti-frictional property and the firmness for wear of the Mi material, only. In this case the comparative analysis of the materials properties and the prediction of its tribologic characteristics in others systems may be accomplished. Really, for M1//M2 system the properties of the M1 and M2 surface are following:
f1 = f1o + (Ilin,1o/(Ilin,1o + Ilin,2o))(f2o-f1o); Ilin,1 = Ilin,1o + + [(f1-f1o)/(f1o + f2o)]Ilin,2o;
f2 = f2o + (Ilin,2o/(Ilin,1o + Ilin,2o))(f1o-f2o); Ilin,2 = Ilin,2o + + [(f2-f2o)/(f1o + f2o)]Ilin,1o;
where the (f1o,Ilin,1o) and (f2o,Ilin,2o) are the values, which were received in corresponding M1//M1 and M2//M2 systems. Then we have the next correlation:
I1 + I2 = I1o + I2o, f1o = f2o = f = (f1oI1o + f2oI2o)/(I1 + I2).
Thus, in the first place, the summary wear in tribologic system is the wear sum of the system elements, which were received on "conventionality scale", and secondly, the wear-friction of tribosystem f(I1 + I2) is the wear-frictional sum of the system elements, which may be calculated on "standard scale". By this thesis the prediction of the tribologic characteristics of materials surface in any systems Mi//Mj may be realized if the experimental dates for systems Mi//Mi and Mj//Mj are determined.
1. The velocity of linear wear Io and the friction coefficient fo of the compositional covers (CC) may be presented in following form:
Io = αosol> + (1-α)olub> + dI(osol>-olub>), fo = αosol> + (1-α)olub>-df(osol>-olub>),
where the values dI = df = d = 4(1-α)α2 [1-k(1-kn)] is the relative synergic effect of the corresponding properties, the symbol α is denotes the volume share of solid CC component in two-component (solid + lubricant) approach, and the parameters k and kn are the dimensional and nano-structural factors, accordingly [1-4].
If the values IoCB and foCB are the counter-body (CB) tribologic properties according to "standard scale" (by conditions IoCB>Io and foCB >fo), then we have
I = α´o´sol> + (1-α´)olub> + d´(o´sol>-olub>), f = α´o´sol> + (1-α´)olub>-d´(o´sol>-olub>),
where α´ = α + Dα, o´sol> = osol>-DIsol>, o´sol> = o´sol> + Dfsol.
Taking into consideration the most possible correlations kCB @ k @ 0,5; knCB @ kn @ 0 and neglecting of members, which are contained (Dα)2 and (Dα)3, we have the next relation for relative synergic effect d´ @ 2(1-α)α2 -2α(3α-2)Dα = d - Dd, where the value Dd is the change of the synergic effect amplitude. Then the changes of the CC tribologic properties are following:
I - Io = (Dα-Dd)(osol>-olub>) + (α + d)DIsol, f - fo = (Dα + Dd)(osol>-olub>) + (α-d)Dfsol.
In these correlations the members contained of little values DdDfsol, DαDfsol , DdDIsol and DαDIsol were neglected.
It´s determined, by fixed α the relation for (f-fo) is increase when the Dα, (osol>-olub>) and Dfsol are increase. The dependences (I-Io) are contains maximum with coordinates [(I-Io), α]max. By increasing the values Dα, (osol>-olub>), and DIsol the coordinate (I-Io) is increase, too, but second coordinate αmax is decrease.
It´s note, this qualitative dates are may be used for prediction of LL substances for with necessary CC tribologic properties [5, 6].
2. In accordance with "concentration wave" model the velocity of linear wear Io and the friction coefficient fo of the compositional covers (CC) may be presented in following form:
Io = αosol> + (1-α)olub> + dI(osol>-olub>), fo = αosol> + (1-α)olub> - df(osol>-olub>),
where the values dI = df = d = 4(1-α)α2 [1-k(1-kn)] is the relative synergic effect of the corresponding properties, the symbol α is denotes the volume share of solid CC component in two-component (solid + lubricant) approach, and the parameters k and kn are the dimensional and nano-structural factors.
If the values (Iol.lub,fol.lub) are the conventional characteristics of the liquid lubricant (LL) according to "conventionality scale" (by conditions Iol.lub o and fol.lub >fo), then we have
I = α´osol> + (1-α´)o´lub> + d´(osol>-o´lub>), f = α´osol> + (1-α´)o´lub>-d´(osol>-o´lub>),
where: α´ = α-Dα, o´lub> = olub> + DIlub>, and o´lub> = o´lub> -Dflub .
Taking into consideration the most possible correlations k @ 0,5; kn @ 0 and neglecting of members, which are contained the (Dα)2 and (Dα)3 fragments, we have the next relation for relative synergic effect d´ @ 2(1-α)α2 + 2α(3α-2)Dα = d + Dd, where the value Dd is the change of the synergic effect amplitude. Then the changes of the CC properties are following:
I-Io = -(Dα + Dd)(osol>-olub>)-(1-α-d)DIsol, f-fo = -(Dα-Dd)(osol>-olub>)-(1-α + d)Dfsol.
It´s note, that in these correlations the members contained of little values DdDfsol, DαDfsol , DdDIsol and DαDIsol were neglected.
It´s determined, by fixed α the relation for (f-fo) is increase when the Dα, (osol>-olub>) and Dfsol are increase. The dependences (I-Io) are contains maximum with coordinates [(I-Io), α]max. By increasing the values Dα, (osol>-olub>), and DIsol the coordinate (I-Io) is increase, too, but second coordinate αmax is decrease.
This qualitative dates are may be used for prediction of new CC with necessary tribologic properties [5, 6].
The work is submitted to the International Scientific Conference “Modern high technologies ”, SPAIN (Tenerife), November 21–28, 2014, came to the editorial office оn 07.11.2014.