Question

b. Materials engineers at NASA Glenn Research Center have designed a metal alloy, GRCop- 84, for use as the liner in a combustion chamber of a rocket engine. The overall composition of the alloy is: 88 atom5% Cu; 8 atom% Cr; 4 atom% Nb. Using the Hume-Rothery rules, evaluate all of the following information to predict whether Nb will form a complete solid solution in Cr. atomic radius. nm valence(s) ENstructure Cu .128 Cr.125 Nb 143

Answer 1

0 AGiven -łhdt Compostion of alloq: 88 atom . cu 4 atom t. Nb adfusm Valence S)ENShuctune l+. 21 1,9 Fcc BCC Bcc Cu128 C6.125 Nbo,43 know Nb en fom cơmpleta solid soluton în G we have b check 3 cases -thay The Bcc stouctune values Fuy cY, Nb aria same Botha u Sarno Hence -thA ·case îs ok by usngmula below - ahmîc ite -fadf calculated Nb 0.143

2 0,143 X 12.SZ 7. cose oi):ElechoN eg atty v Relative Valen- In Hhis caue f Complete solubilrhy elecho negaivitly and alen must be same Relahye Valency EledsoNegaiviti +3, +6 both але .samL almost bolh >ame dua sama s cohe is alkho salis-fi ed conclude that -Hence Nb onm a coplete solid solutivn 1 G