Summary of the invention
For the problems referred to above, the object of the present invention is to provide a kind ofly have that density is high, method that tungsten and copper intermiscibility globular tungsten powder good and that specific conductivity is high are prepared tungsten-copper alloy.
The technical scheme solving the problems of the technologies described above is as follows:
Globular tungsten powder is prepared the method for tungsten-copper alloy, comprises the following steps:
Step 1, get and 10%-20% copper powder mix with globular tungsten powder 70%-80% end by weight percentage, wherein the diameter at globular tungsten powder end is 2-8 μ m, copper powder is that electrolytic copper powder median size is 45 μ m, with 100~130r/min speed ball milling mixed powder 5-10h, when ball milling mixed powder, steel ball is 5: 1 with the ratio of compound;
Step 2, mixed powder is colded pressing and made blank under 200-900MPa pressure condition, make the relative density of blank reach 75%-85%;
Step 3, blank is carried out to vacuum outgas, the blank of vacuum outgas is put into airtight plumbago crucible, and in plumbago crucible, puts into copper material, and copper material is put the upper surface in blank, the quality of copper material be step 1 interalloy copper mass 1.1-1.5 doubly;
Step 4, employing aluminum oxide carry out landfill to plumbago crucible, heat-up rate with 5-10 DEG C/min heats up to the blank in plumbago crucible and copper material, while being heated to 900-1000 DEG C, is incubated 2 hours, then continues to heat up, at 1200-1300 DEG C, ooze copper, insulation 1-3h makes tungsten-copper alloy.
Adopt such scheme, the present invention makes tungsten copper powder mix after blank, without first sintered skeleton, but be directly contained in airtight plumbago crucible, while being heated to 900-1000 DEG C, be incubated 2 hours, then continue to heat up, at 1200-1300 DEG C, ooze copper, and due to when the base, in blank, having electrolytic copper powder and relative density is 75%-85%, electrolytic copper powder at this temperature in blank also liquefies, the mobility of copper phase and the filling properties to hole are improved, it is high that thereby the tungsten-copper alloy that makes to make has density, tungsten and the advantage that copper intermiscibility is good and specific conductivity is high.
Preferably, in described step 4, in the time that intensification temperature approaches copper fusing point, in plumbago crucible, pass into shielding gas.By shielding gas, not only reduce the oxidation of copper under molten state, and under the effect of protection pressure gas; help flowing of copper phase; promoted the filling of copper relative porosity factor, therefore, the copper-tungsten that makes to make has advantages of that density is high, tungsten and copper intermiscibility is good and specific conductivity is high.
Preferably, passing into before shielding gas in plumbago crucible, first to vacuumizing in plumbago crucible.In vacuum environment, pass into after shielding gas; in plumbago crucible, be the atmosphere of shielding gas completely, blank and copper material in this atmosphere, the effect that can not be oxidized completely; and increased the gas pressure power of plumbago crucible, make copper more easily evenly infiltration in tungsten basal body.
Embodiment
Globular tungsten powder is prepared the method for tungsten-copper alloy, comprises the following steps:
Step 1, get and 10%-20% copper powder mix with globular tungsten powder 70%-80% end by weight percentage, wherein the diameter at globular tungsten powder end is 2-8 μ m, copper powder is that electrolytic copper powder median size is 45 μ m, with 100~130r/min speed ball milling mixed powder 5-10h, when ball milling mixed powder, steel ball is 5: 1 with the ratio of compound, and steel ball and compound adopt such ratio, is that the mixing in order to make compound can be more even.
Step 2, mixed powder is colded pressing and made blank under 200-900MPa pressure condition, make the relative density of blank reach 75%-85%.
Step 3, blank is carried out to vacuum outgas, will after the blank base of vacuum outgas, put into airtight plumbago crucible, and in plumbago crucible, put into copper material, copper material is put the upper surface in blank, the quality of copper material be step 1 interalloy copper mass 1.1-1.5 doubly.
Step 4, employing aluminum oxide carry out landfill to plumbago crucible, with the heat-up rate of 5-10 DEG C/min, the blank in plumbago crucible and copper material are heated up, and at 1200-1300 DEG C, ooze copper, and insulation 1-3h makes tungsten-copper alloy.In step 4, in the time that intensification temperature approaches copper fusing point, in plumbago crucible, pass into shielding gas.The flow velocity of shielding gas is 150-400ml/min, and shielding gas is nitrogen.Passing into before shielding gas in plumbago crucible, first to vacuumizing in plumbago crucible.
Except above step, the present invention also comprises the making to globular tungsten powder end, and detailed process is as follows:
Selecting raw material powder is tungsten powder in irregular shape, 200 orders sieve, purity > 99.9%, raw material powder is sent in airflow milling and ground, obtain the powder of the one-tenth individual particle of good dispersity, even particle size distribution, the separation wheel rotating speed of airflow milling is 2500-7000 rev/min, and grinding chamber pressure is 0.1MPa-1MPa, powder feeding rate 0.1-20kg/ hour.After raw material tungsten powder is fully dry, pack into for powder chamber, after excluding air with atmospheric isolation.Induction plasma producer first vacuumizes, and then passes into working gas Ar, starts induction plasma producer, sets up stable argon plasma torch, and original tungsten powder passes through H
2send into plasma torch, the powder sending quantity of tungsten powder is 50g/min, and the pressure of center gas (Ar) is 0.5Mpa-0.7MPa, and the flow of center gas Ar is 0.8m
3/ h, the defeated gas (H that helps
2) pressure be 0.5MPa-0.7MPa, the defeated gas (H that helps
2) flow be 0.8m
3/ h, the power loading on ruhmkorff coil is 40KW-90KW; The pressure of the main working gas argon gas when steady running of argon plasma torch is 0.5MPa-0.6MPa, and the pressure of back work gas hydrogen is 0.5MPa-0.6Mpa; The tungsten powder particles that enters argon plasma torch absorbs a large amount of heat and gasification, cracking rapidly in a short period of time, forms spherical droplets under capillary effect, and the high-temperature zone that speeds away enters water-cooled holding tank and solidifies.Form tiny spherical tungsten particle.Tungsten powder is collected respectively from heat exchange chamber bottom and secondary collecting chamber and filtering net.
Tungsten powder particle-size before and after nodularization and pattern are carried out to observation analysis with JSM-6700F high resolution scanning electron microscope, count the shared per-cent of spheroidal globule after spheroidizing, each sample random sampling statistics 3 times, then get the nodularization rate of arithmetical av as this sample, and measure the tap density of Cement Composite Treated by Plasma front and back tungsten powder with BT-300 powder tapping Density Measuring Instrument.Raw material tungsten powder particles is coacervate in irregular shape or loose porous granule, is the spherical of rule through said process tungsten powder after treatment, and smooth surface.In addition, after nodularization, the particle diameter of tungsten powder is also less than raw material tungsten powder.Plasma-treating technology is described except comprising nodularization process. the process of in addition tungsten powder being carried out to refinement.Refinement reason is because raw material tungsten powder is not single full particle, but loose POROUS TUNGSTEN particle or the coacervate that formed by many small-particles.These coacervates or unsound particle are sharply heated the rapid dissociation of meeting and make tungsten powder refinement in plasma arc.In addition, tungsten powder coexists in high-temperature zone gasification and melting process. and less nano particle may be the product of tungsten vapour condensation.Tungsten powder has experienced gasification-condensation process, and therefore product tungsten powder obtains refinement.
Embodiment 1:
Get by weight percentage and 10% copper powder mix with globular tungsten powder 80% end, the diameter at globular tungsten powder end is 2-8 μ m, and the median size of copper powder is 45 μ m, with 100r/min speed ball milling mixed powder 10h.Mixed powder is colded pressing and made blank under 900MPa pressure condition, make the relative density of blank reach 85%.Blank is carried out to vacuum outgas, the blank of vacuum outgas is put into airtight plumbago crucible, and in plumbago crucible, put into copper material, copper material is put the upper surface in blank, and the quality of copper material is 1.5 times of step 1 interalloy copper mass.Adopt aluminum oxide to carry out landfill to plumbago crucible, heat-up rate with 10 DEG C/min heats up to the blank in plumbago crucible and copper material, in the time of 900-1000 DEG C, is incubated 2 hours, then continues to heat up, when temperature approaches copper fusing point, first to vacuumizing in plumbago crucible.In plumbago crucible, pass into shielding gas again, the flow velocity of shielding gas is 150ml/min, and shielding gas is nitrogen.At 1200 DEG C, ooze copper, insulation 1h makes tungsten-copper alloy.
Embodiment 2:
Get by weight percentage and 15% copper powder mix with globular tungsten powder 75% end, the diameter at globular tungsten powder end is 2-8 μ m, and the median size of copper powder is 45 μ m, with 120r/min speed ball milling mixed powder 7h.Mixed powder is colded pressing and made blank under 400MPa pressure condition, make the relative density of blank reach 80%.Blank is carried out to vacuum outgas, and the blank of vacuum outgas is put into airtight plumbago crucible, and in plumbago crucible, puts into copper material, and copper material is put the upper surface in blank, and the quality of copper material is 1.4 times of step 1 interalloy copper mass.Adopt aluminum oxide to carry out landfill to plumbago crucible, heat-up rate with 8 DEG C/min heats up to the blank in plumbago crucible and copper material, in the time of 900-1000 DEG C, is incubated 2 hours, then continues to heat up, when temperature approaches copper fusing point, first to vacuumizing in plumbago crucible.In plumbago crucible, pass into shielding gas again, the flow velocity of shielding gas is 250ml/min, and shielding gas is nitrogen.At 1250 DEG C, ooze copper, insulation 2h makes tungsten-copper alloy.
Embodiment 3:
Get by weight percentage and 20% copper powder mix with globular tungsten powder 70% end, the diameter at globular tungsten powder end is 2-8 μ m, and the median size of copper powder is 45 μ m, with 130r/min speed ball milling mixed powder 5h.Mixed powder is colded pressing and made blank under 200MPa pressure condition, make the relative density of blank reach 75%.Blank is carried out to vacuum outgas, and the blank of vacuum outgas is put into airtight plumbago crucible, and in plumbago crucible, puts into copper material, and copper material is put the upper surface in blank, and the quality of copper material is 1.1 times of step 1 interalloy copper mass.Adopt aluminum oxide to carry out landfill to plumbago crucible, heat-up rate with 5 DEG C/min heats up to the blank in plumbago crucible and copper material, in the time of 900-1000 DEG C, is incubated 2 hours, then continues to heat up, when temperature approaches copper fusing point, first to vacuumizing in plumbago crucible.In plumbago crucible, pass into shielding gas again, the flow velocity of shielding gas is 250ml/min, and shielding gas is nitrogen.At 1300 DEG C, ooze copper, insulation 3h makes tungsten-copper alloy.