M = 1; m = 0.1; n = 3; Pr = 3; Ec = 0.1; N = 0.5; lp = 0.01; Bi = 0.5; wf = 100; om = 0.1; %w1 = 10; w2 = 10;
syms w1 w2
facecolors = {'g', 'r', 'b', 'k', 'm'};
nvalues = [3 3.7 5 5.7 8.9];
for nidx = 1:length(nvalues)
n = nvalues(nidx);
Cpf = 3594;rhof = 1063;kf = 0.492;Cps1 = 960;sigmaf = 4.3*(10^-5);rhos1 = 2810;ks1 = 173;sigmas1 = 26.77*10^6;Cps2 = 893;rhos2 = 2720;ks2 = 222;sigmas2 = 34.83*10^6;
phi1 = (w1/rhos1)./( (w1/rhos1) + (w2/rhos2) + (wf/rhof));
phi2 = (w2/rhos2)./( (w1/rhos1) + (w2/rhos2) + (wf/rhof)) ;
phi = phi1 + phi2;rhos = ((rhos1*w1) + (rhos2*w2))./(w1 + w2);Cps = ((Cps1 * w1) + (Cps2 * w2))./(w1 + w2);
A1 = (1-phi)^-2.5;A2 = ( 1- phi + phi*(rhos/rhof));A4 = ( 1- phi+phi*((rhos*Cps)/(rhof*Cpf)));
C1 = ( (ks1+(n-1)*kf-(n-1)*phi1*(kf-ks1))/(ks1+(n-1)*kf+phi1*(kf-ks1)) )*kf;
A3 = (ks2+(n-1)*C1-(n-1)*phi2*(C1-ks2))/(ks2+(n-1)*C1+phi2*(C1-ks2));
C2 = ( (sigmas1+2*sigmaf-2*phi1*(sigmaf-sigmas1))/(sigmas1+2*sigmaf+phi1*(sigmaf-sigmas1)))*sigmaf;
A5 = (sigmas2+2*C2-2*phi2*(C2-sigmas2))/(sigmas2+2*C2+phi2*(C2-sigmas2));
fsurf(A3,[0 10 0 10],'LineWidth',2,'EdgeColor','none', 'facecolor', facecolors{nidx} );
hold on
end
view(30,30);
xlabel ('$\textbf{w}_1$','color','blue','Fontsize',14,'FontWeight', 'bold', 'interpreter', 'latex');
ylabel ('$\textbf{w}_2$','color','blue','Fontsize',10,'FontWeight', 'bold', 'interpreter', 'latex');
zlabel ('$\textbf{k}_{hnf}\textit{f}$','color','blue','Fontsize',14,'FontWeight','bold', 'interpreter', 'latex');
axis on; box on;
ax = gca;
ax.BoxStyle = 'full';
ax.XAxis.LineWidth = 2;
ax.YAxis.LineWidth = 2;
ax.ZAxis.LineWidth = 2;
legend({'\color{green}\bfSpherical','\color{red}\bfBrick','\color{blue}\bfCylindrical','\color{black}\bfPlatelet','\color{magenta}\bfBlade'},'Box','off');
I had to make some guesses about what you were trying to do with the labels, I could not figure out the \k_f -- I had to guess italics.
