摘要:
High strength, thermoplastically processable (TPF) amorphous alloys composed of Beryllium and at least one ETM and at least one LTM, as well as methods of processing such alloys are provided. The TPF alloys of the invention demonstrate good glass forming ability, low viscosity in the supercooled liquid region (SCLR), a low processing temperature, and a long processing time at that temperature before crystallization.
摘要:
A process and apparatus for thermoplastic casting of a suitable glass forming alloy is provided. The method and apparatus comprising thermoplastically casting the alloy in either a continuous or batch process by maintaining the alloy at a temperature in a thermoplastic zone, which is below a temperature, Tnose, (where, the resistance to crystallization is minimum) and above the glass transition temperature, Tg, during the shaping or moulding step, followed by a quenching step where the item is cooled to the ambient temperature. A product formed according to the thermoplastic casting process is also provided.
摘要:
A manufacturing process for casting amorphous metallic parts separates the filling and quenching steps of the casting process in time. The mold is heated to an elevated casting temperature at which the metallic alloy has high fluidity. The alloy fills the mold at the casting temperature, thereby enabling the alloy to effectively fill the spaces of the mold. The mold and the alloy are then quenched together, the quenching occurring before the onset of crystallization in the alloy. With this process, compared to conventional techniques, amorphous metallic parts with higher aspect ratios can be prepared.
摘要:
The surface features of an article are replicated by preparing a master model having a preselected surface feature thereon which is to be replicated, and replicating the preselected surface feature of the master model. The replication is accomplished by providing a piece of a bulk-solidifying amorphous metallic alloy, contacting the piece of the bulk-solidifying amorphous metallic alloy to the surface of the master model at an elevated replication temperature to transfer a negative copy of the preselected surface feature of the master model to the piece, and separating the piece having the negative copy of the preselected surface feature from the master model.
摘要:
A metallic article is fabricated by providing a die and a piece of a bulk-solidifying amorphous metallic alloy having a glass transition temperature. The bulk-solidifying amorphous metallic alloy is heated to a forming temperature of from about 0.75 T.sub.g to about 1.2 T.sub.g and forced into the die cavity at the forming temperature under an external pressure of from about 260 to about 40,000 pounds per square inch, thereby deforming the piece of the bulk-solidifying amorphous metallic alloy to a formed shape that fills the die cavity. Preferably, a pressure is applied to the piece of the bulk-solidifying amorphous metallic alloy as it is heated, and the heating rate is at least about 0.1.degree. C. per second. The die may be a male die or a female die. When the die has a re-entrant comer therein, the formed shape of the bulk-solidifying amorphous metallic alloy is mechanically locked to the die.
摘要:
A casting charge of a bulk-solidifying amorphous alloy is cast into a mold from a temperature greater than its crystallized melting temperature, and permitted to solidify to form an article. The oxygen content of the casting charge is limited to an operable level, as excessively high oxygen contents produce premature crystallization during the casting operation. During melting, the casting charge is preferably heated to a temperature above a threshold temperature to eliminate heterogeneous crystallization nucleation sites within the casting charge. The casting charge may be cast from above the threshold temperature, or it may be cooled to the casting temperature of more than the crystallized melting point but not more than the threshold temperature, optionally held at this temperature for a period of time, and thereafter cast.
摘要:
Two pieces of metal are joined together using an amorphous metallic joining element. In the joining operation, the joining element is placed between the two pieces to be joined. The joining element and adjacent regions of the pieces being joined are given a joining processing sequence of heating to a joining temperature, forcing the two pieces together for a period of time, and cooling. The joining element has a composition that is amorphous after the processing is complete. The joining element composition is also selected such that, after interdiffusion of elements from the pieces being joined into the joining element during processing, the resulting composition is amorphous after cooling.
摘要:
A pest electrocution device includes a mechanical portion and an electronic portion. The mechanical portion includes a base member with sidewalls defining a basin, a flexible sheet member secured on the base member, and a conductive plate member which is attached on the top face of the flexible sheet member and has at least part of it not overlapping the shoulder of the sidewalls. A pair of opposing metal contacts are respectively fastened on the bottom face of the flexible sheet member and on the base member. The metal contacts are coupled to the trigger input of the electronic circuit portion while the conductive plate member is coupled to the high voltage output of the electronic circuit portion. The electronic circuit portion includes a timer for producing a timing and control signal and a high voltage generator for generating a high voltage current. The electronic circuit portion further includes a latch circuit which records the status of the device for the user to check the status at any time. The electronic circuit portion also includes a pulse generation circuit for generating a high voltage, low current pulse train.
摘要:
Method and appartaus are disclosed for stimulating the heart with a pacemaker in response to a nonambient temperature of a body, which is sensed, for example, in the right ventricle of the heart. The pacemaker stimulates the heart at one of at least three different nominal rates which have been selected by the physician for the various activity levels of the patient. When the heart is stimulated at an interim rate for mild or brief exercise conditions, the activity level of the patient is sensed using a motion sensor. A control circuit terminates a predetermined time period selected for the pacemaker to stimulate at the interim rate when the sensed level is less than a predetermined activity level. The stimulation rate of the heart is controlled by the nonambient body temperature sensed in the right ventricle of the heart, but the sensed motion or activity level of the patient is used to terminate the interim time period when the sensed activity level of the patient does not correspond to the level of activity intended for the selected stimulation rate.