What is Phosphorus
Phosphorus is the 15th chemical element. It is in the third period of the periodic table, group VA.
Phosphorus is widely distributed in the biosphere. It ranks among the top 10 in terms of crustal content. Phosphorus is widely present in animal and plant tissues. It is also one of the most abundant elements in the human body, accounting for about 1% of the body weight. The adult body contains about 600-900g of phosphorus. Among them, 85.7% of phosphorus is concentrated in bones and teeth. The remaining phosphorus is distributed in various tissues and body fluids of the whole body, half of which exists in muscle tissue. Phosphorus not only constitutes the composition of the human body, but also participates in very important metabolic processes in life activities. As an important constituent element of human cell DNA and RNA, phosphorus is a very important element for the body.
| I | O | |||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 1 H |
II | III | IV | V | VI | VII | 2 He |
||||||||||
| 2 | 3 Li |
4 Be |
5 B |
6 C |
7 N |
8 O |
9 F |
10 Ne |
||||||||||
| 3 | 11 Na |
12 Mg |
III | IV | V | VI | VII | VIII | I | II | 13 Al |
14 Si |
15 P |
16 S |
17 Cl |
18 Ar |
||
| 4 | 19 K |
20 Ca |
21 Sc |
22 Ti |
23 V |
24 Cr |
25 Mn |
26 Fe |
27 Co |
28 Ni |
29 Cu |
30 Zn |
31 Ga |
32 Gc |
33 As |
34 Se |
35 Br |
36 Kr |
| 5 | 37 Rb |
38 Sr |
39 Y |
40 Zr |
41 Nb |
42 Mo |
43 Tc |
44 Ru |
45 Rh |
46 Pd |
47 Ag |
48 Cd |
49 In |
50 Sn |
51 Sb |
52 Te |
53 I |
54 Xe |
| 6 | 55 Cs |
56 Ba |
57-71 La-Lu |
72 Hf |
73 Ta |
74 W |
75 Re |
76 Os |
77 Ir |
78 Pt |
79 Au |
80 Hg |
81 Tl |
82 Pb |
83 Bi |
84 Po |
85 At |
86 Rn |
| 7 | 87 Fr |
88 Ra |
89-103 Ac-Lr |
104 Rf |
105 Db |
106 Sg |
107 Bh |
108 Hs |
109 Mt |
110 Ds |
111 Rg |
112 Uub |
||||||
| La-Lu | 57 La |
58 Ce |
59 Pr |
60 Nd |
61 Pm |
62 Sm |
63 Eu |
64 Gd |
65 Tb |
66 Dy |
67 Ho |
68 Er |
69 Tm |
70 Yb |
71 Lu |
|||
| Ac-Lr | 89 Ac |
90 Th |
91 Pa |
92 U |
93 Np |
94 Pu |
95 Am |
96 Cm |
97 Bk |
98 Cf |
99 Es |
100 Fm |
101 Md |
102 No |
103 Lr |
|||
- Item Name: Phosphorus
- Element Symbol: P
- Atomic Number: 15
- Atomic Weight: 30.97
- Atomic Radius: 115pm
- Density: 1.82g/cm3
- Melting Point: 44.1°C
- Boiling Point: 280.5°C
- Electronic Layout: [Ne]3s23p3
The Atomic Structure of Phosphorus
The Role of Phosphorus in Superalloys
In superalloys, phosphorus has both beneficial and detrimental effects. These different effects depend on the phosphorus content and the type of alloy. In the following, we will introduce these two functions of phosphorus separately.
The Beneficial Effects of Phosphorus
An appropriate amount of phosphorus in superalloys can improve the creep resistance and durability of the alloy. Phosphorus will segregate to the grain boundaries in the alloy. This segregation increases the bonding force between the grain boundaries, which increases the creep resistance and durability of the alloy.
However, the content of phosphorus in the alloy is not as high as possible. On the one hand, phosphorus has a detrimental effect on the alloy. On the other hand, with the increase of phosphorus content, the creep resistance of the alloy tends to increase first and then decrease. Studies have shown that when the phosphorus content reaches 0.005% to 0.016%, the creep resistance of the alloy reaches the maximum. The figure below shows the relationship between the creep properties of the alloy and the phosphorus content.
The Relationship between the Creep Properties of the Alloy and the Phosphorus Content
In the study of Inconel 718, the researchers smelted four composition ratios with phosphorus content of 0.0008%, 0.01%, 0.016% and 0.04%. The final results show that the phosphorus content of 0.016% brings the best creep resistance to the alloy.
The Harmful Effects of Phosphorus
Phosphorus in superalloys can cause segregation of elements in the alloy during solidification. This segregation leads to the precipitation of Laves phase in the alloy. The Laves phase is a harmful phase. It acts as a channel for crack formation and propagation in the alloy. At the same time, it consumes the niobium element in the alloy. This reduces the number of strengthening phases and significantly reduces the tensile properties of the alloy during aging treatment.
For cast superalloys, the alloy is shaped by solidification. Therefore, it retains the negative effects of phosphorus to the greatest extent. The deformed superalloy can partially eliminate this negative effect after hot working or heat treatment. Therefore, it suffers from relatively limited harmful effects of phosphorus content.
After testing, when the phosphorus content is below 0.008%, it has little effect on the performance of the alloy. Once the phosphorus content exceeds this amount, the performance of the alloy will be significantly reduced.
Conclusion
Phosphorus plays two roles in superalloys at the same time. It can increase the creep resistance and durability of the alloy by increasing the crystal bonding force. It will also make the alloy more prone to precipitate harmful phases and reduce the tensile properties of the alloy. In actual projects, we should choose the appropriate phosphorus content according to different alloys to maximize the performance of the alloy.
We have our own smelting furnace, which can precisely control the composition of the alloy. If you have any procurement requirements for superalloys, please contact us.
