LA OMC EN POCAS PALABRAS ;
2.2.3 El Acuerdo sobre los Aspectos de los Derechos de Propiedad Intelectual relacionados con el Comercio (ADPIC)
101
102
Plate 4.1: Micrograph of Cu-10wt%Al (base alloy) (x400)
Plate 4.2: Micrograph of Cu-10wt%Al +0.5wt%Ti (x400)
4.1
4.2
Cu9Al4 α + γ2 phases
α-phase
β-phase
103
Plate 4.3: Micrograph of Cu-10%Al +2.0wt%Ti (x400)
Plate 4.4: Micrograph of Cu-10%Al +4.5wt%Ti (x400)
4.3
4.4
𝛽
𝛼
104
Plate 4.5: Micrograph of Cu-10%Al +5.0wt%Ti (x400)
Plate 4.6: Micrograph of Cu-10%Al +5.5wt%Ti (x400)
4.5
4.6
105
Plate 4.7: Micrograph of Cu-10%Al +7.5wt%Ti (x400)
Plate 4.8: Micrograph of Cu-10%Al +10wt%Ti (x400)
4.7
4.8
𝛼
𝛽
106
Plate 4.9: Micrograph of Cu-10%Al +7.0wt%Ti (x400)
Plate 4.10: Micrograph of Cu-10%Al+6.0wt%Ti. (x400)
4.9
4.10
107
Plate 4.11: Micrograph of Cu-10%Al+6.5wt%Ti. (x400)
Plate4.2 to Plate 4.11 show the microstructure of copper-10% aluminium (Cu-10%Al) alloy treated with (0.5 to 10%) wt% titanium. From the micrographs, addition of titanium to Cu-10%Al alloy stabilizes the formation of 𝛽-phases which showed small grains of alpha (𝛼) and few amount of kappa (k) phase grains in black lamellar form. The large size of 𝛼-phase with white colour and small amount of 𝜸2-phase and 𝛽- phase were observed from the alloys as titanium increased in the microstructure.As the composition of titanium atom increased, it was also observed that 𝜸2-phase was suppressed which brought about improvement in the alloy properties.
4.11
α +κeutectoid
108
Plate 4.12: Micrograph of Cu-10%Al+0.5wt%Zr. (x400)
Plate 4.13: Micrograph of Cu-10%Al+3.0wt%Zr. (x400)
𝜶 𝜶phase
4.12
4.13
βphase
109
Plate 4.14: Micrograph of Cu-10%Al+5.5wt%Zr. (x400)
Plate 4.15: Micrograph of Cu-10%Al+6.0wt%Zr (x400)
4.14
4.15
110
Plate 4.16: Micrograph of Cu-10%Al+7.0wt%Zr. (X400)
Plate 4.17: Micrograph of Cu-10%Al+6.5wt%Zr. (x400)
𝜶 𝒑𝒉𝒂𝒔𝒆
𝜶 𝒑𝒉𝒂𝒔𝒆
4.16
4.17
111
Plate 4.18: Micrograph of Cu-10%Al+9.5wt%Zr. (x400)
Plate 4.19: Micrograph of Cu-10%Al+10wt%Zr. (x400)
𝜷 𝒑𝒉𝒂𝒔𝒆
𝜶 𝒑𝒉𝒂𝒔𝒆
𝜶 + 𝒌 𝒑𝒉𝒂𝒔𝒆
4.19
𝜷 𝒑𝒉𝒂𝒔𝒆 𝜶 𝒑𝒉𝒂𝒔𝒆
4.18
112
Plate 4.20: Micrograph of Cu-10%Al+7.5wt%Zr. (x400)
Plate 4.21: Micrograph of Cu-10%Al+8.0wt%Zr. (x400)
𝜶 +k phase
𝜶 𝒑𝒉𝒂𝒔𝒆 𝜷 𝒑𝒉𝒂𝒔𝒆 𝜶+k phase
4.20
4.21
113
Plate4.12 to Plate 4.21 show the microstructure of Cu-10%Al alloy treated with (0.5 to 10) wt% zirconium. The 𝛼-phase increased in size as the composition of zirconium increased. This leads to formation of fine lamellar form of kappa (k)precipitates present in the microstructures. 𝛽-phase decreased in size as the weight composition of zirconium atom increased thereby allowing little or no 𝛾2
phase to precipitate. Presence of sparse distribution of kappa precipitates in the predominated 𝛼 matrix caused smaller grains to development which leads to improvement in the alloy properties.
Plate 4.22: Micrograph of Cu-10%Al+0.5wt%Mn. (x400)
𝜶 𝒑𝒉𝒂𝒔𝒆 4.22
𝛽-phase
114
Plate 4.23: Micrograph of Cu-10%Al+1.0wt%Mn. (x400)
Plate 4.24: Micrograph of Cu-10%Al+1.5wt%Mn. (x400)
𝜶 𝒑𝒉𝒂𝒔𝒆
β phase 𝜷
𝜶phase
4.24 4.23
115
Plate 4.25: Micrograph of Cu-10%Al+2.0wt%Mn. (x400)
Plate 4.26: Micrograph of Cu-10%Al+2.5wt%Mn. (x400)
𝜶 𝒑𝒉𝒂𝒔𝒆
𝜷phase
4.25
𝜶 𝒑𝒉𝒂𝒔𝒆
𝜷 𝒑𝒉𝒂𝒔𝒆
4.26
116
Plate 4.27: Micrograph of Cu-10%Al+3.0wt%Mn. (x400)
Plate 4.28: Micrograph of Cu-10%Al+3.5wt%Mn. (x400)
𝒌 𝒑𝒉𝒂𝒔𝒆
4.27
4.28
𝜶phase
117
Plate 4.29: Micrograph of Cu-10%Al+4.0wt%Mn (x400)
Plate 4.30: Micrograph of Cu-10%Al+4.5wt%Mn. (x400)
4.30
4.29
𝛼+k-phase
118
Plate 4.31: Micrograph of Cu-10%Al+5.0wt%Mn. (x400)
Plate4.22 to Plate 4.31 show the microstructure of Cu-10%Al alloy treated with (0.5 to 5.0) wt% manganese.Because of the solubility of manganese in copper,the addition of manganese to the alloy refines the grain structure and stabilizes the 𝛽-phases. It also suppressed the formation of 𝛾2 phase. Manganese forms intermetallic phase with aluminum which produces the fine structure.
𝜷 𝒑𝒉𝒂𝒔𝒆
𝜶 𝒑𝒉𝒂𝒔𝒆
4.31
119
Plate 4.32: Micrograph of Cu-10%Al +0.5wt%V. (x400)
Plate 4.33: Micrograph of Cu-10%Al +1.0wt%V (x400) 4.32
𝜷 𝒑𝒉𝒂𝒔𝒆 4.33
𝛼-phase
𝛽-phases
120
Plate 4.34: Micrograph of Cu-10%Al +1.5wt%V (x400)
Plate 4.35: Micrograph of Cu-10%Al +2.0wt%V (x400)
4.34
4.35
121
Plate 4.36: Micrograph of Cu-10%Al +2.5wt%V (x400)
Plate 4.37: Micrograph of Cu-10%Al +3.0wt%V (x400)
4.36
4.37
K phase
122
Plate 4.38: Micrograph of Cu-10%Al +3.5wt%V (x400)
Plate 4.39: Micrograph of Cu-10%Al +4.0wt%V (x400)
4.38
4.39
𝜷phase α +κ eutectoid
K phase
123
Plate 4.40: Micrograph of Cu-10%Al+4.5wt%V. (x400)
Plate 4.41: Micrograph of Cu-10%Al+5.0wt%V. (x400)
𝜷 𝒑𝒉𝒂𝒔𝒆 𝜶phase 4.40
4.41
124
Plate4.32 to Plate 4.41 represent the micrographs of Cu-10%Al alloy treated with (0.5 to 5.0) wt% vanadium. The micrographs show that as vanadium increased the quantity of 𝛼-phase increase in copper matrix. The presence of more vanadium in the alloy matrix provided increased in nucleation sites for the transformation of 𝛽-phase. Vanadium reduced kinetics of kappa phase precipitates due to small grains of 𝛼-phase, this smaller grains of 𝛼-phase lead to formation of α +κ eutectoid which brought about improvement in alloy properties.
Plate 4.42: Micrograph of Cu-10%Al +0.5wt%W (x400)
𝜶 𝒑𝒉𝒂𝒔𝒆 4.42
𝛽-phase
125
Plate 4.43: Micrograph of Cu-10%Al +3.0wt%W (x400)
Plate 4.44: Micrograph of Cu-10%Al +4.5wt%W (x400)
𝜷phase 4.43
𝜷 𝒑𝒉𝒂𝒔𝒆
𝜶 𝒑𝒉𝒂𝒔𝒆 4.44
126
Plate 4.45: Micrograph of Cu-10%Al +5.0wt%W (x400)
Plate 4.46: Micrograph of Cu-10%Al+6.0wt%W. (x400)
4.45
𝜷 𝒑𝒉𝒂𝒔𝒆 𝜶 𝒑𝒉𝒂𝒔𝒆 4.46
Κ phase
127
Plate 4.47: Micrograph of Cu-10%Al +6.5wt%W (x400)
Plate 4.48: Micrograph of Cu-10%Al +7.0wt%W (x400)
4.47
4.48
k-phase αphase
Κ phase
128
Plate 4.49: Micrograph of Cu-10%Al+8.0wt%W. (x400)
Plate 4.50: Micrograph of Cu-10%Al +9.5wt%W. (x400)
4.50 4.49
β phase
α + κ phase
129
Plate 4.51: Micrograph of Cu-10%Al +4.0wt%W (x400)
Plate4.42 to Plate 4.51 show the microstructure of Cu-10%Al alloy treated with (0.5 to 10) wt.% tungsten.The overall grain size was reduced considerably with increase in tungsten content. Addition of tungsten to the alloy refines the grain structure and stabilizes the 𝛽-phases. It also suppressed the formation of 𝛾2 phase.
This could be attributed to the presence of sparse distribution of suspected 𝛼-phase precipitates in a predominant 𝛽 matrix which brought improvement in the properties.
4.51
β phase
130
Plate 4.52: Micrograph of Cu-10%Al+0.5wt%Cr. (x400)
Plate 4.53: Micrograph of Cu-10%Al+1.0wt%Cr. (x400)
𝛽 − phase
𝜶 𝒑𝒉𝒂𝒔𝒆 4.52
4.53
131
Plate 4.54: Micrograph of Cu-10%Al+1.5wt%Cr. (x400)
Plate 4.55: Micrograph of Cu-10%Al+2.0wt%Cr. (x400)
𝜶phase
𝜷 𝒑𝒉𝒂𝒔𝒆 𝜶 𝒑𝒉𝒂𝒔𝒆
4.54
4.55
132
Plate 4.56: Micrograph of Cu-10%Al+2.5wt%Cr. (x400)
Plate 4.57: Micrograph of Cu-10%Al+3.0wt%Cr. (x400)
𝜶 𝒑𝒉𝒂𝒔𝒆
𝜷 𝒑𝒉𝒂𝒔𝒆
𝜶 𝒑𝒉𝒂𝒔𝒆
4.56
4.57
133
Plate 4.58: Micrograph of Cu-10%Al+3.5wt%Cr. (x400)
Plate 4.59: Micrograph of Cu-10%Al+5.0wt%Cr. (x400)
𝜶 𝜷
𝜶
4.59
𝜷 𝒑𝒉𝒂𝒔𝒆
𝜶phase
4.58
134
Plate 4.60: Micrograph of Cu-10%Al+7.5wt%Cr. (x400)
Plate 4.61: Micrograph of Cu-10%Al+7.0wt%Cr. (x400)
Plate4.52 to Plate 4.61 show the microstructure of Cu-10%Al alloy treated with (0.5 to 10) wt% chromium. The micrographs show more dispersed precipitates of
4.60
4.61
𝐾 − 𝑃𝑎𝑠𝑒 α + κ
phase
135
𝛼-phase in a more refined 𝛽- matrix with finer grain structure. The pearlite structure has been altered, with the lamellar structure transforming to give 𝑘-phases at the grain boundaries and with no undesirable 𝛾2 phase, which has deleterious effect on mechanical properties of aluminum bronze.
Plate 4.62: Micrograph of Cu-10%Al+0.5wt%Mo. (x400) 4.62
𝛽-phase
136
Plate 4.63: Micrograph of Cu-10%Al+1.0wt%Mo. (x400)
Plate 4.64: Micrograph of Cu-10%Al+1.5wt%Mo. (x400)
𝜶phase
𝜷 𝒑𝒉𝒂𝒔𝒆
4.63
4.64
𝛽-phase
137
Plate 4.65: Micrograph of Cu-10%Al+2.0wt%Mo. (x400)
Plate 4.66: Micrograph of Cu-10%Al+2.5wt%Mo. (x400)
𝜷phase
𝜶
4.66 4.65
α phase
138
Plate 4.67: Micrograph of Cu-10%Al+3.0wt%Mo. (x400)
Plate 4.68: Micrograph of Cu-10%Al+3.5%Mo. (x400)
𝜷
𝜶
4.67
4.68
α phase
139
Plate 4.69: Micrograph of Cu-10%Al+5.5wt%Mo (x400)
Plate 4.70: Micrograph of Cu-10%Al+7.0wt%Mo. (x400)
𝜷
𝜶
4.70 4.69
α + κ phase
140
Plate 4.71: Micrograph of Cu-10%Al+7.5wt%Mo. (x400)
Plate4.62 to Plate 4.71 show the microstructure of Cu-10%Al alloy treated with (0.5 to 10) wt% molybdenum. Molybdenum stabilized 𝛽-phase and hence increased toughness and strength. The microstructure showed that molybdenum increased the quantity of 𝛼-phase in Cu-10%Al alloy system.Presence of sparse distribution of kappa precipitates in the predominated 𝛼 + k caused smaller grains to increase in the microstructure which enhanced mechanical properties of the alloy.
4.71
α + κ phase
141
Plate 4.72: Micrograph of Cu-10%Al +0.5wt%Ni. (x400)
Plate 4.73: Micrograph of Cu-10%Al +1.0wt%Ni (x400) 4.72
4.73
𝛼phase
𝛾2 phase
β phase
α -phase
142
Plate 4.74: Micrograph of Cu-10%Al +1.5wt%Ni (x400)
Plate 4.75: Micrograph of Cu-10%Al +2.0wt%Ni (x400)
4.74
4.75
143
Plate 4.76: Micrograph of Cu-10%Al +2.5wt%Ni (x400)
Plate 4.77: Micrograph of Cu-10%Al +3.0%Ni (x400)
4.76
4.77
144
Plate 4.78: Micrograph of Cu-10%Al +3.5wt%Ni (x400)
Plate 4.79: Micrograph of Cu-10%Al +4.0wt%Ni (x400)
4.78
4.79
(𝛼+𝑘) phase
145
Plate 4.80: Micrograph of Cu-10%Al+4.5wt%Ni (x400)
Plate 4.81: Micrograph of Cu-10%Al+5.0wt%Ni (x400)
Plate4.72 to Plate 4.81 represent the micrographs of Cu-10%Al alloy treated with (0.5 to 5.0) wt% nickel. Addition of nickel has a strong influence on the stabilization of 𝛽-phases. Therefore nickel added improved the properties and
𝜷
𝜶
𝜷 𝒑𝒉𝒂𝒔𝒆 4.80
4.81
146
stabilized the effect of 𝛽-phase on the metallurgical structure. It also suppressed the formation of 𝛾2 phase and modifies the characteristics of 𝛽-phases making it more susceptible to corrosion. It forms Ni3Al intermetallic phase with Al which has precipitation hardening effect.
4.3 Structural Analysis with Scanning Electron Microscope (SEM) and