Ceramic liners and and ceramic plungers of drilling mud pumps
A) Ceramic liners and ceramic plungers features:
1,Corrosion-resistant,acid-proof alkali, heat-resistant, it can work in the medium of the drilling mud or other corrosive liquid etc.
2,High hardness, wear resistance,it can resist high pressure mud of sharp or abrasive resistance of the solid particles grinding or scour,such as rock debris,quartz sands,iron ores,scrap iron.
3,Evenly distributed structure for microstructure and smoothly surface will improve the life of the piston.
4,Working pressure is high,more than 52 MPa (7500 PSI), to meet drilling deep well, ultra-deep demand.
B) Ceramic liners and ceramic plungers material and performance index:
Ceramic liner and ceramic plungers take zirconia composite ceramic formulations as the formula,after high pressure forming, sintering and finishing process,a finished products is present out . The composition ofzirconia: 5.4% yttria and 94.6%zirconia ,theaverage particlesize less than 0.5 μm. As zirconia is reputed for its highfracture toughness,it is thusused to improve the atigue strength of the final product. But pure zirconia product tends to be efflorescenceon the surface after long service at 100 to 250 ℃damp environment. As a result,its abrasion resistance and mechanical property declined greatly, no doubt,service life of the product limited.The part of aluminum oxide comprises 99.9% aluminum oxide,with average particle size less than 0.5μm.Aluminum oxide hashigh hardnessand good abrasion performance,but its fracture toughness is low.The product ofaluminum oxideis thus likely to develop cracks. Mixture of zirconia and aluminum oxide through fine process controlrealizes mutual supplementation of these two substances, thusgetting round both efflorescencecommonly seen among zirconia and low fracture toughness commonly seen among aluminum oxide. Massive experiments show that the toughness is maximum when 80 --90% zirconia is added.We select super fine zirconia just to get dense sintering result, and consequently fine finish of the product.
C) Ceramic liners and ceramic plungers performance index:
| Item | Others | Jusheng Petroleum |
| Average grain (μm) | ≤ 7 | ≤ 3 |
| Rockwell hardness (HRA) | ≥ 89.5 | ≥ 91 |
| Bending strength (MPa) | ≥ 350 | ≥ 800 |
| Water absorbability (%) | ≤ 0.05 | ≤ 0.01 |
| Fracture toughness (MPa.M1/2) | ≥ 4 | ≥ 9 |
| Volume density (g/cm3) | ≥ 3.85 | ≥ 5.6 |
| Toughness of working surface | ≥ 0.40 μm when temp ≤ 350℃ | ≤ 0.25μm when temp ≤ 350℃ |
| Wear resistance (laboratory test) |
20 times more than that of high chromium cast iron |
50 times more than that of high chromium cast iron |
| Compression strength (MPa) | ≥ 3000 | ≥ 5000 |
| Thermal shock resistance (temperature crack) | ≥ 350℃ | ≥ 350℃ |
