本文对La在Ni-20Cr-20Co-18W高温合金中的分布及其作用进行了研究.发现La主要富集在晶界上;La显著增加合金在1000℃,39MPa条件下的持久寿命和延伸率以及蠕变激活能.用热蚀刻方法测量了合金的晶界能,用测量电阻率随温度变化的方法测量了合金的空位形成能.从理论上阐述了La降低晶界能和提高空位形成能的作用是改善合金持久性能的主要原因.
The distribution of La in a superalloy Ni-20Cr-20Co.-18W is found out to be enriched mainly along its grain boundaries as oxide and oxysulphide. Some of the oxide may be formed the nuclei of the carbide M_6C. The La improves significantly the stress rupture life under 39 MPa at 1000℃ and raises the creep activation energy of the superalloy. The grain boundary energy was evaluated by thermal etching technique and the vacancy formation energy was measured by temperature dependence of resistivity. A theoretical interpretation was made that the contribution of La to decreasing boundary energy and increasing the vacancy formation energy is the main causes of the improvement of stress rupture property of the superalloy.
参考文献
| [1] | |
| [2] | |
| [3] | |
| [4] | |
| [5] | |
| [6] | |
| [7] | |
| [8] |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%