^{1}

^{*}

^{2}

Aluminum-copper titanium di-boride [Al-4Cu
_{-x}TiB
_{2}] composite (x = 1%, 1.75%, 2.5%) is prepared successfully by centrifugal casting. Samples pin of diameter 8 mm, 10 mm, & 12 mm are prepared with help of special purpose die. An experimental parameter analysis is obtained for various load and speed combinations on pinon wear disc testing machine. A larger volume fraction of particles can be attained near the wear surface via centrifugal casting. The volume fraction of the heavier titanium di-boride is controlled by inertial forces upon centrifugal processing the semisolid composite. Mathematical Regression Analysis is carried out to calculate wear. Greasy material facilitates heat transfer on the counter side material. Comparative study facilitates wear predictions of Al-4Cu
_{-x}TiB
_{2} metal matrix composite for various practical applications.

The difficulties in the development of particulate metal matrix such as poor wettability, inhomogeneous distribution of reinforcement particles, formation of unwanted reaction products at the interface between the matrix and reinforcement, etc. have led to attempts to synthesis new generation in composites. Among the composites metal matrix composites have become popular in the recent years. Functionally graded materials (FGMs) are spatial composites that display discrete or continuously varying composition over a definable geometrical length [

An Experimental set up used to prepare Al-TiB_{2} metal matrix composite is shown is

Wear and friction testing machine is shown in

facilitates study of friction and wear characteristics in sliding contact under desired conditions. Sliding occurs between the stationary pin and a rotating disc. Normal load, rotational speed and wear track diameter can be varied to suit the test conditions. Tangential frictional force and wear are monitored with electronic sensors and recorded on computer .These parameters are available as function of load and speed. Reading of wear are taken after making all the necessary connections and Sliding speed is calculated as follows Sliding speed = π × D × N/60,000.

Cross section Area of rod = π × d^{2}/4 where, D = Diameter of wear track in mm. N = Disc speed in rpm. T = Test duration in sec, d = diameter of specimen rod.

Let, W = Wear in micron, L = Load in N, V = Sliding Speed in m/s, T = Test duration in sec.

K = Proportionality Constant, a, b, & c are the index of load, speed & time respectively,W_{1} and W_{2 }are wears corresponding to loads L_{1}, L_{2}; Sliding speeds V_{1}, V_{2} and testing time T_{1}, T_{2}

Equation of wear is –W = K × L^{a} × V^{b} × T^{c}

^{b} × T^{c} = Cont).

W_{1}/W_{2} = (L_{1}/L_{2})^{a}

ln(W_{1}/W_{2}) =a × ln(L_{1}/L_{2})

a = ln(W_{1}/W_{2})/ln(L_{1}/L_{2})

Regression Analysis: WEAR versus LOAD

The regression equation is

WEAR = –1.77 + 0.437 LOAD

Predictor Coef SE Coef T P VIF

Constant –1.7670 0.6073 –2.91 0.101

LOAD 0.43750 0.01685 25.97 0.001 1.000

S = 0.370355 R-Sq = 99.7% R-Sq(adj) = 99.6%

Similarly, b is

b= ln (W_{1}/W_{2}) / ln(V_{1}/V_{2})

where, k × L^{a} × T^{c} = Constant

Regression Analysis: WEAR versus SLIDING SPEED

The regression equation is

WEAR = –52.0 + 33.4 SLIDING SPEED

Predictor Coef SE Coef T P VIF

Constant –52.0010 0.0022 –23758.06 0.000

SLIDING SPEED 33.4093 0.0005 73904.47 0.000 1.000

S = 0.000423587 R-Sq = 100.0% R-Sq(adj) = 100.0%

c = ln (W_{1}/W_{2})/ln (T_{1}/T_{2}) where k × L^{a} × V^{b} = Constant.

Regression Analysis: WEAR versus TEST TIME

The regression equation is

WEAR = 11.5 + 0.0800 TEST TIME

Predictor Coef SE Coef T P

Constant 11.5000 0.8660 13.28 0.006

TEST TIME 0.080000 0.003162 25.30 0.002

S = 0.707107 R-Sq = 99.7% R-Sq(adj) = 99.5%