Super high temperature molybdenum disilicide zirconia composite heating element and its preparation method

Abstract

This invention relates to a hyperthermal molybdenum disilicon zirconium oxide compound heater, belonging to the heating material technology. This heater uses molybdenum disilicon zirconium oxide two-phage reticulated structure compound material as matrix, concretely it uses (Mo1-x,Wx)Si2 as one phage of the two-phage compound material, where X=0-0.5, and uses yttrium oxide / calcium oxide stabilized zirconium oxide powder as the other phage, where the content of the zirconium oxide powder is 30-70vol% of the compound material. The process comprises: charging the above two-phage compound material and sintering aid, adding in adhesive for pugging, extrusion molding, drying, burning and filming treatment, so as to obtain the product, wherein: the bar produced by organic adhesive molding and drying needs degreasing process under 0.1MPa hydrogen gas pressure, at 300-600Deg C for 3-30 hours, where the burning temperature is 1500-1750Deg C. The invention can produce high efficient and long-life heater at more than 1850Deg C.

Description

Technical field

[0001] The invention belongs to the heating material technology, and mainly proposes an ultra-high temperature molybdenum disilicide zirconia composite heating element and a preparation method thereof. Background technique

[0002] Molybdenum disilicide material has good high temperature oxidation resistance because it can form a dense protective film on the surface at a high temperature above 1000 ° C. It has been widely used as a high temperature heating element used in an atmospheric environment. Its own The highest heat-resistant temperature can reach above 1800°C. Zirconia fast ion conductor is also a high-temperature heating element used in an oxidizing atmosphere. The operating temperature can reach above 2000 degrees. However, it has the disadvantage of being non-conductive at low temperatures. A lot of inconvenience has come, so the scope of application is small. With the advancement of science and technology, higher requirements have been placed o...

Examples

Embodiment and comparative example 1

[0026] Specimen type

[0027]After sintering the materials with different content of zirconia, the strength and heat resistance comparison tests of the rods were carried out. The sintering temperature was kept at 1700 degrees for 2 hours. The results showed that: compared with the single-phase materials B1 and B4, the composite material was sintered to obtain a heating body rod with uniform microstructure, fine grains, and high strength of the rod, while the single-phase material had many pores and grains. Bulky and low strength. From the heat resistance test results, it can be seen that the heat resistance of the material is improved with the addition of zirconia, especially when the zirconia is continuous, the heat resistance of the composite material is significantly improved from 1750 degrees of single-phase molybdenum disilicide B1 1900 degrees to S1. Similarly, the introduction of zirconia also affects the electrical properties of the material at room temperat...

Embodiment and comparative example 2

[0029] Specimen type

[0030] Creep resistance tests were carried out on the rods sintered with different zirconia contents. The test conditions are test temperature / 1000°C, load stress / 100MPa. Table 3 shows the strain values ​​of the five samples after 10 hours and 20 hours after the start of the experiment. It can be seen that the content of zirconia and its microstructural characteristics directly affect the creep degree of the sample. Ten hours after the start of the experiment, the strain of S1 was 0.000031, B1 was 0.0026, B2 was 0.0020, B3 was 0.00010, and B4 was 0.000009. It can be seen that the addition of zirconia can improve the high temperature creep resistance of molybdenum disilicide, especially the added phase When the structure is continuous, the creep resistance is nearly 2 orders of magnitude higher than that of the single-phase molybdenum disilicide material; moreover, the deformation difference between the two will become larger and larger as time...

Embodiment and comparative example 3

[0032] Specimen type

[0033] For the heating element, the thermal shock resistance of the heating element material is evaluated by the current shock resistance performance. The test plan is to heat the heating element to 1500 degrees under the action of alternating current, power on for 30 seconds and then power off for 10 seconds, and so on until the material is destroyed. , the number of cycles to characterize the thermal shock resistance of the heating element. Table 4 shows the thermal shock resistance test results of heating elements with different zirconia content. It can be seen that with the addition of zirconia, the thermal shock resistance of the heating element is affected, especially when the amount of zirconia added is too much, it is When molybdenum disilicide is discontinuous, such as B4, the thermal shock resistance of the material becomes very poor, and the actual application life will be very short.

Technical field

[0001] The invention belongs to the heating material technology, and mainly proposes an ultra-high temperature molybdenum disilicide zirconia composite heating element and a preparation method thereof. Background technique

[0002] Molybdenum disilicide material has good high temperature oxidation resistance because it can form a dense protective film on the surface at a high temperature above 1000 ° C. It has been widely used as a high temperature heating element used in an atmospheric environment. Its own The highest heat-resistant temperature can reach above 1800°C. Zirconia fast ion conductor is also a high-temperature heating element used in an oxidizing atmosphere. The operating temperature can reach above 2000 degrees. However, it has the disadvantage of being non-conductive at low temperatures. A lot of inconvenience has come, so the scope of application is small. With the advancement of science and technology, higher requirements have been placed o...

Examples

Embodiment and comparative example 1

[0026] Specimen type

[0027]After sintering the materials with different content of zirconia, the strength and heat resistance comparison tests of the rods were carried out. The sintering temperature was kept at 1700 degrees for 2 hours. The results showed that: compared with the single-phase materials B1 and B4, the composite material was sintered to obtain a heating body rod with uniform microstructure, fine grains, and high strength of the rod, while the single-phase material had many pores and grains. Bulky and low strength. From the heat resistance test results, it can be seen that the heat resistance of the material is improved with the addition of zirconia, especially when the zirconia is continuous, the heat resistance of the composite material is significantly improved from 1750 degrees of single-phase molybdenum disilicide B1 1900 degrees to S1. Similarly, the introduction of zirconia also affects the electrical properties of the material at room temperat...

Embodiment and comparative example 2

[0029] Specimen type

[0030] Creep resistance tests were carried out on the rods sintered with different zirconia contents. The test conditions are test temperature / 1000°C, load stress / 100MPa. Table 3 shows the strain values ​​of the five samples after 10 hours and 20 hours after the start of the experiment. It can be seen that the content of zirconia and its microstructural characteristics directly affect the creep degree of the sample. Ten hours after the start of the experiment, the strain of S1 was 0.000031, B1 was 0.0026, B2 was 0.0020, B3 was 0.00010, and B4 was 0.000009. It can be seen that the addition of zirconia can improve the high temperature creep resistance of molybdenum disilicide, especially the added phase When the structure is continuous, the creep resistance is nearly 2 orders of magnitude higher than that of the single-phase molybdenum disilicide material; moreover, the deformation difference between the two will become larger and larger as time...

Embodiment and comparative example 3

[0032] Specimen type

[0033] For the heating element, the thermal shock resistance of the heating element material is evaluated by the current shock resistance performance. The test plan is to heat the heating element to 1500 degrees under the action of alternating current, power on for 30 seconds and then power off for 10 seconds, and so on until the material is destroyed. , the number of cycles to characterize the thermal shock resistance of the heating element. Table 4 shows the thermal shock resistance test results of heating elements with different zirconia content. It can be seen that with the addition of zirconia, the thermal shock resistance of the heating element is affected, especially when the amount of zirconia added is too much, it is When molybdenum disilicide is discontinuous, such as B4, the thermal shock resistance of the material becomes very poor, and the actual application life will be very short.