将粉末粒径为50～100 µm的Ni80Cr20(60 wt％)合金粉末与Cr203(20 wt%)、Ag(10 wt%)和共晶BaF2/CaF2(10 wt%)三种粉末（自润滑相）按PS304成分配料后进行高能球磨，并将球磨粉末冷等静压到Ni基高温合金轴表面，经真空烧结成PM304涂层。研究表明，烧结温度对PM304的相对密度与拉伸强度有较大影响，当烧结温度从800℃增大到1100℃时，PM304的相对密度从80%增大到94%,拉伸强度从7 MPa增大到47 MPa。当烧结温度为1100℃时，PM304涂层组织细小致密，润滑相Cr203粒子尺寸为100 nm左右、BaF2/CaF2粒子尺寸为1 µm左右、Ag粒子尺寸小于5 µm，拉伸强度拉比PS304伸强度高出33％，在温度范围200～800℃的平均热膨胀系数为12.6×10-6 K-1。当烧结温度从1100℃增大到1200℃时，PM304的相对密度与拉伸强度变化不大，但NiCr相明显长大。
PM304 composite comprised of NiCr (80/20) matrix (60 wt%) combined with Cr2O3 (20 wt%), Ag (10 wt%) and eutectic BaF2/CaF2 (10 wt%) as solid self-lubricants additives has been prepared by high-energy ball milling and powder metallurgy. Experimental results showed that the sintering temperature had great influence on relative density and tensile strength of the PM304 composite. The relative density and tensile strength of PM304 increased rapidly with the increase of sintering temperature from 800°C to 1100°C. The size of Cr2O3 and BaF2/CaF2 of PM304 composite sintered at 1100°C was less than 1 μm, and that of Ag particles was below 5 μm, the relative density was 94%, and the mean tensile strength 47 MPa, 33% greater than that of PS304.
参考文献
| [1] | |
| [2] | |
| [3] | |
| [4] | |
| [5] | |
| [6] | |
| [7] |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%