Chapter 11, Problem 11.26P

Interpretation Introduction

(a)

Interpretation:

The total $\beta$ % and the % eutectic microconstituent for $10\%Sn$ at room temperature needs to be determined.

Concept Introduction:

The compound formula of Lead-Tin alloy is designated by 'Pb-Sn'.

1. It appears in solid form.
2. It appears in various shapes like wire, ingot, foil, bar, ribbon etc.
3. It appears in silver color.
4. Its melting point is 182-215 degree Celsius.

Lead-Tin are widely used as soldering alloys. They are compatible for all types of uses.

Answer to Problem 11.26P

The Total % $\beta$ and the % eutectic microconstituent at room temperature for $10\%Sn$ is 8.2% and 0% respectively.

Explanation of Solution

Given:

$10\%Sn$

Calculations:

From the graph,

For % $\beta$ = $\frac{10-2}{99-2}$ =8.2%

% Eutectic = 0.

Thus, the evaluated value of % $\beta$ and the % eutectic microconstituent at room temperature for 10% Sn is calculated as 8.2% and 0% respectively.

Interpretation Introduction

(b)

Interpretation:

The total $\beta$ % and the % eutectic microconstituent for $20\%Sn$ at room temperature needs to be determined.

Concept Introduction:

The compound formula of Lead-Tin alloy is designated by 'Pb-Sn'.

1. It appears in solid form.
2. It appears in various shapes like wire, foil, bar, ribbon etc.
3. It appears in silver color.
4. Its melting point is 182-215 degree Celsius.

Lead-Tin are widely used as soldering alloys. They are compatible for all types of uses.

Answer to Problem 11.26P

The Total % $\beta$ and the % eutectic microconstituent at room temperature for $20\%Sn$ is 18.6% and 2.3% respectively.

Explanation of Solution

Given:

$20\%Sn$

Calculations:

From the graph,

For % $\beta$ = $\frac{20-2}{99-2}=$ 18.6%

% Eutectic = $\frac{50-19}{61.9-19}$ =2.3%

The evaluated value of % $\beta$ and the % eutectic microconstituent at room temperature for 20% Sn is calculated as 18.6% and 2.3% respectively.

Interpretation Introduction

(c)

Interpretation:

The total $\beta$ % and the % eutectic microconstituent for $50\%Sn$ at room temperature needs to be determined.

Concept Introduction:

The compound formula of Lead-Tin alloy is designated by 'Pb-Sn'.

1. It appears in solid form.
2. It appears in various shapes like wire, foil, bar, ribbon etc.
3. It appears in silver color.
4. Its melting point is 182-215 degree Celsius.

Lead-Tin are widely used as soldering alloys. They are compatible for all types of uses.

Answer to Problem 11.26P

The Total % $\beta$ and the % eutectic microconstituent at room temperature for $50\%Sn$ is 49.5% and 72.3% respectively.

Explanation of Solution

Given:

$50\%Sn$

Calculations:

From the diagram,

For % $\beta$ = $\frac{50-2}{99-2}=49.5\%$

% Eutectic = $\frac{60-19}{61.9-19}=72.3\%$

The evaluated value of % $\beta$ and the % eutectic microconstituent at room temperature for 50% Sn is calculated as 49.5% and 72.3% respectively.

Interpretation Introduction

(d)

Interpretation:

The total $\beta$ % and the % eutectic microconstituent for $60\%Sn$ at room temperature needs to be determined.

Concept Introduction:

The compound formula of Lead-Tin alloy is designated by 'Pb-Sn'.

1. It appears in solid form.
2. It appears in various shapes like wire,foil, bar, ribbon etc.
3. It appears in silver color.
4. Its melting point is 182-215 degree Celsius.

Lead-Tin are widely used as soldering alloys. They are compatible for all types of uses.

Answer to Problem 11.26P

The Total % $\beta$ and the % eutectic microconstituent at room temperature for $60\%Sn$ is 59.8% and 95.6% respectively.

Explanation of Solution

Given:

$60\%Sn$

Calculations:

From the graph,

For % $\beta$ = $\frac{60-2}{99-2}=59.8\%$

% Eutectic = $\frac{97.5-19}{61.9-19}=95.6\%$

The evaluated value of % $\beta$ and the % eutectic microconstituent at room temperature for 60% Sn is calculated as 59.8% and 95.6% respectively.

Interpretation Introduction

(e)

Interpretation:

The total $\beta$ % and the % eutectic microconstituent for $80\%Sn$ at room temperature needs to be determined.

Concept Introduction:

The compound formula of Lead-Tin alloy is designated by 'Pb-Sn'.

1. It appears in solid form.
2. It appears in various shapes like wire, foil, bar, ribbon etc.
3. It appears in silver color.
4. Its melting point is 182-215 degree Celsius.

Lead-Tin are widely used as soldering alloys. They are compatible for all types of uses.

Answer to Problem 11.26P

The Total % $\beta$ and the % eutectic microconstituent at room temperature for $80\%Sn$ is 80.4% and 49.2% respectively.

Explanation of Solution

Use spreadsheet to tabulate the % total $\beta$ and % eutectic micro constituent as in table (1)

Composition of % $Sn$ in entire $Pb-sn$ phase diagram	Tensile Strength ( $MPa$)	Total % $\beta$ phase	% Eutectic
10	30	8.2	0
20	40	18.6	2.3
50	50	49.5	72.3
60	60	59.8	95.6
80	70	80.4	49.6
95	80	95.9	7

Given:

$80\%Sn$

Calculations:

From the graph:

For % $\beta$ = $\frac{80-2}{99-2}=80.4\%$

% Eutectic = $\frac{97.5-80}{97.5-61.9}=49.2\%$

Thus, by using the expression of eutectic, the required value obtained is 49.2%.

Interpretation Introduction

(f)

Interpretation:

The total $\beta$ % and the % eutectic microconstituent for $95\%Sn$ at room temperature needs to be determined.

Concept Introduction:

The compound formula of Lead-Tin alloy is designated by 'Pb-Sn'.

1. It appears in solid form.
2. It appears in various shapes like wire, foil, bar, ribbon etc.
3. It appears in silver color.
4. Its melting point is 182-215 degree Celsius.

Lead-Tin are widely used as soldering alloys. They are compatible for all types of uses.

Answer to Problem 11.26P

The Total % $\beta$ and the % eutectic microconstituent at room temperature for $95\%Sn$ is 95.9% and 7.0% respectively.

Explanation of Solution

Given:

$95\%Sn$

Calculations:

For % $\beta$ = $\frac{95-2}{99-2}=95.9\%$

% Eutectic = $\frac{97.5-95}{97.5-61.9}=7.0\%$

(Mention Graph)

After Studying the graph of tensile strength vs % $\beta$ we can conclude that as tensile strength increases to its maximum value of 7800psi at % $\beta$ = 60%.

The evaluated value of % $\beta$ and the % eutectic microconstituent at room temperature for 95% Sn is calculated as 95.9% and 7.0% respectively.