CN102534316B - Al-Mo-W-Ti intermediate alloy and preparing method thereof - Google Patents

Abstract

The invention discloses an Al-Mo-W-Ti intermediate alloy comprising the following components by weight percent: 21 to 31percent of Mo; 10 to 18 percent of W; 5 to 16 percent of Ti; 0 to 0.1 percent of Fe; 0 to 0.15 percent of Si; 0 to 0.1 percent of C; 0 to 0.1 percent of O; 0 to 0.04 percent of S; and Al in balancing amount. The invention further provides a preparing method for the Al-Mo-W-Ti intermediate alloy. The smelting process of the preparing method comprises two steps; compared with the conventional outside-furnace smelting method, the preparing method has the advantage that ingredients obtained according to the preparing method are more uniform; particularly, Al and Ti are added twice in each of the two steps, so that the uniformity of the ingredients is better than that of ingredients obtained according to a method in which Al is added once. Moreover, the invention further adopts a unique smelting method in which a carbon crucible coated with a yttrium oxide layer serves as a smelting container in a vacuum furnace, so that compared with the conventional method in which a water-cooling copper crucible is required to be adopted, the invention has the advantages that the manufacturing cost is greatly reduced, and the introduction of impurities can be controlled better.

Description

A kind of aluminium molybdenum tungsten titanium master alloy and preparation method thereof

Technical field

The present invention relates to a kind of master alloy and preparation method thereof, relate in particular to a kind of aluminium molybdenum tungsten titanium master alloy of smelting use and preparation method thereof.

Background technology

Along with the development of titanium alloy, adopt master alloy to add in the smelting of titanium alloy more and more general.Master alloy for adding requires segregation-free, and without metal inclusion, foreign matter content is low as much as possible.

Present master alloy adopts single stage method to smelt more, and the alloy of smelting not only foreign matter content is higher, and homogeneity is not fine.

Summary of the invention

The object of the present invention is to provide a kind of aluminium molybdenum tungsten titanium master alloy and preparation method thereof, the foreign matter content of aluminium molybdenum tungsten titanium master alloy can reach titanium alloy and smelt the requirement of adding, and the preparation method of master alloy can more easily control.

A kind of aluminium molybdenum tungsten titanium master alloy provided by the invention comprises following component: Mo21～31%, W10～18%, Ti5～16%, Fe≤0.1%, Si≤0.15%, C≤0.1%, O≤0.1%, S≤0.04%, and surplus is Al; Wherein, described per-cent is weight percentage; Described master alloy is by being prepared as follows the method preparation:

1) according to MoO ₃100 parts, WO ₃34～46 parts, Al154～191 part, CaF ₂0～61 part, KClO ₃0～38 part, Ti10～30 part take each starting material;

2) with the shove charge at normal temperatures of each starting material, adopt the outer aluminothermy smelting method of stove to carry out the first step and smelt;

3) with 18～20 parts of Al, 10～30 parts the Ti starting material and smelt the blank obtain be placed in together vacuum melting furnace and carry out vacuum melting in step 1), the smelting temperature of vacuum melting is 1450～1600 ℃, vacuum tightness is less than 0.67Pa, the rear refining 6～15 minutes of seething with excitement in short-term under the high temperature of 1500 ℃ of furnace charge fusing, and carry out alloy casting under vacuum condition.

Preferably, comprise following component: Mo21～31%, W10～18%, Ti5～16%, Fe≤0.05%, Si≤0.07%, C≤0.05%, O≤0.05%, S≤0.01%, surplus is Al; Wherein, described per-cent is weight percentage.

The present invention also provides a kind of preparation method of aluminium molybdenum tungsten titanium master alloy, comprises the steps:

1) according to MoO ₃100 parts, WO ₃34～46 parts, Al154～191 part, CaF ₂25～61 parts, KClO ₃24～38 parts, Ti10～30 part take each starting material;

2) with the shove charge at normal temperatures of each starting material, adopt the outer aluminothermy smelting method of stove to carry out the first step and smelt;

3) with 18～20 parts of Al, 10～30 parts the Ti starting material and smelt the blank obtain be placed in together vacuum melting furnace and carry out vacuum melting in step 1), the smelting temperature of vacuum melting is 1450～1600 ℃, vacuum tightness is less than 0.67Pa, the rear refining 6～15 minutes of seething with excitement in short-term under the high temperature of 1500 ℃ of furnace charge fusing, and carry out alloy casting under vacuum condition.

Preferably, when described vacuum oven carries out melting, adopt carbon crucible filling furnace charge, and apply one deck yttrium oxide in described carbon crucible.

The present invention is by adopting two-step approach to smelt, the outer smelting method of the existing stove of comparing, the composition that obtains is more even, especially adopts in two steps and adds at twice respectively Al and Ti, make that the homogeneity of composition more once adds better; In addition, the present invention has also adopted to use in vacuum oven and has been coated with the carbon crucible of one deck yttrium oxide as unique smelting process of smelting vessel, like this, compares with the water-cooled copper crucible that will adopt in the past, manufacturing cost reduces greatly, and can be better the introducing of controlling impurity.

Embodiment

The present invention adopts two-step approach to smelt aluminium molybdenum tungsten titanium master alloy, mainly comprises the steps:

1) according to MoO ₃100 parts, WO ₃34～46 parts, Al154～191 part, CaF ₂0～61 part, KClO ₃0～38 part, Ti10～30 part take each starting material;

2) with the shove charge at normal temperatures of each starting material, adopt the outer aluminothermy smelting method of stove to carry out the first step and smelt;

3) with 18～20 parts of Al, 10～30 parts the Ti starting material and smelt in the first step primary products obtain and be placed in together vacuum melting furnace and carry out vacuum melting, the smelting temperature of vacuum melting is 1450～1600 ℃, vacuum tightness is less than 0.67Pa, after furnace charge is melted to 1/4 to 2/5, can be filled with argon gas, furnace pressure is remained in 50～80Pa, to prevent that in stove, solution too seethes with excitement.After furnace charge in stove melts fully, make and carry out short time high temperature boiling refining in stove, refining time is 6～15 minutes, temperature 〉=1500 ℃.Until the alloy liquid level is tranquil, overflow without bubble, then when being 1480～1550 ℃, the alloy solution temperature casts.

In step 3), what the present invention adopted in vacuum oven is the carbon crucible, and is coated with one deck yttrium oxide at the internal surface of crucible.Owing to adopting such container to load the alloy of smelting, compared with adopt the water-cooled copper crucible in the past on the one hand, production cost reduces greatly, and, also can keep good stability due to yttrium oxide under the condition of 1450～1600 ℃, therefore can prevent from introducing other impurity in the process of smelting, the control of the homogeneity of the tissue of alloy and the content of impurity plays a good role.

In addition, the present invention adds starting material Al and Ti in two steps in step 3), can make more disposable the wanting better of adding in the first step of homogeneity of composition.In addition, in the present invention, the yttrium oxide of coating preferably adopts analytically pure yttrium oxide.

In addition, in step 2) in, employing be that the outer thermite reaction of stove is smelted method, low as much as possible in order to make N content, for example, lower than 0.001%, adopt vacuum aluminum thermal response smelting process in stove, specific practice is:

The starting material of step 1) weighing are put in crucible, then crucible is placed in vacuum oven, and connect the portfire of igniting, vacuumize, and then be filled with helium, light a fire by portfire, thereby carry out thermite reaction.

Below, come by specific embodiment that the present invention is further described, the concrete method that adopts is same as the above-mentioned method.

Embodiment 1

The batching weight take Kg as unit, MoO ₃100Kg, WO ₃38.3Kg, Al69.2Kg, CaF ₂55.8Kg, KClO ₃19.2Kg take each starting material; Add 19.3KgAl and 17.9KgTi in the refining of step 3), smelt through two steps the alloy component that obtains as follows:

Mo is 26.3%, W is 13.13%, Ti is 8.38%, Fe is 0.09%, Si is 0.07%, O is 0.09%, S is 0.05%, N is 0.02%; Surplus is Al; Wherein, the per-cent here is weight percentage.

It is that stove is smelted outward that the two step smelting method the first steps of the present embodiment adopt.

Embodiment 2

The batching weight take Kg as unit, MoO ₃100Kg, WO ₃38.3Kg, Al55.2Kg, Ti4Kg take each starting material; Add 18.3KgAl and 30.8KgTi in the refining of step 3), smelt through two steps the alloy component that obtains as follows:

Mo is 26.28%, W is 13.55%, Ti is 15.6%, Fe is 0.08%, Si is 0.06%, O is 0.07%, S is 0.05%, N is 0.002%; Surplus is Al; Wherein, the per-cent here is weight percentage.

It is vacuum metling in stove that the two step smelting method the first steps of the present embodiment adopt.

Embodiment 3

The batching weight take Kg as unit, MoO ₃100Kg, WO ₃41Kg, Al55.7Kg, CaF ₂56.8Kg, KClO ₃19Kg takes each starting material; Add 18.8KgAl and 17.9KgTi in the refining of step 3), smelt through two steps the alloy component that obtains as follows:

Mo is 25.92%, W is 14.01%, Ti is 15.91%, Fe is 0.06%, Si is 0.05%, O is 0.06%, S is 0.05%, N is 0.002%; Surplus is Al; Wherein, the per-cent here is weight percentage.

It is vacuum metling in stove that the two step smelting method the first steps of the present embodiment adopt.

Claims (4)

1. an aluminium molybdenum tungsten titanium master alloy, is characterized in that, comprise following component: Mo21～31%, W10～18%, Ti5～16%, Fe≤0.1%, Si≤0.15%, C≤0.1%, O≤0.1%, S≤0.04%, surplus is Al; Wherein, described per-cent is weight percentage; Described master alloy is by being prepared as follows the method preparation:

1) according to MoO ₃100 parts, WO ₃34～46 parts, Al154～191 part, CaF ₂0～61 part, KClO ₃0～38 part, Ti10～30 part take each starting material;

2) with the shove charge at normal temperatures of each starting material, adopt the outer aluminothermy smelting method of stove to carry out the first step and smelt;

3) with 18～20 parts of Al, 10～30 parts the Ti starting material and smelt the blank obtain be placed in together vacuum melting furnace and carry out vacuum melting in step 1), the smelting temperature of vacuum melting is 1450～1600 ℃, vacuum tightness is less than 0.67Pa, the rear refining 6～15 minutes of seething with excitement in short-term under the high temperature of 1500 ℃ of furnace charge fusing, and carry out alloy casting under vacuum condition.

2. aluminium molybdenum tungsten titanium master alloy as claimed in claim 1, is characterized in that, comprise following component: Mo21～31%, W10～18%, Ti5～16%, Fe≤0.05%, Si≤0.07%, C≤0.05%, O≤0.05%, S≤0.01%, surplus is Al; Wherein, described per-cent is weight percentage.

3. the preparation method of an aluminium molybdenum tungsten titanium master alloy, is characterized in that, comprises the steps:

1) according to MoO ₃100 parts, WO ₃34～46 parts, Al154～191 part, CaF ₂0～61 part, KClO ₃0～38 part, Ti10～30 part take each starting material;

2) with the shove charge at normal temperatures of each starting material, adopt the outer aluminothermy smelting method of stove to carry out the first step and smelt;

3) with 18～20 parts of Al, 10～30 parts the Ti starting material and smelt the blank obtain be placed in together vacuum melting furnace and carry out vacuum melting in step 1), the smelting temperature of vacuum melting is 1450～1600 ℃, vacuum tightness is less than 0.67Pa, the rear refining 6～15 minutes of seething with excitement in short-term under the high temperature of 1500 ℃ of furnace charge fusing, and carry out alloy casting under vacuum condition.

4. method as claimed in claim 3, is characterized in that, when described vacuum oven carries out melting, adopts carbon crucible filling furnace charge, and apply one deck yttrium oxide in described carbon crucible.