Ultrasonic Method For Detecting Banding In Metals
A method for non-destructively detecting the presence of banded regions in a metal is described. The method involves sending an ultrasonic wave into the metal and obtaining reflected signals. The reflected signals are compared with each other to determine variations in signal intensity. A banded region within the metal can be observed as a weaker reflected signal than a reflected backwall signal, thus accurately identifying a location of banding within the metal. Metal articles with a low percent of banding are also described.
1 . A method for non-destructively detecting the presence of banded regions in a metal comprising:
sending an ultrasonic wave into said metal and obtaining reflected signals.
2 - 3 . (canceled)
4 . A method for detecting material aberrations in metal comprising:
directing pulsed signals of a predetermined frequency at an incident surface of said metal and obtaining reflected signals.
5 . The method of claim 4 , wherein said reflected signals are compared with each other to determine any intensity fluctuations in said reflected signals.
6 - 8 . (canceled)
9 . The method of claim 4 , wherein said metal is a sputter target.
10 . (canceled)
11 . The method of claim 4 , wherein said metal is tantalum or an alloy thereof.
12 - 14 . (canceled)
15 . The method of claim 4 , wherein said pulsed signals are ultrasonic.
16 . The method of claim 4 , wherein said pulsed signals are in the range of from about 2 MHz to about 20 MHz.
17 - 19 . (canceled)
20 . The method of claim 4 , wherein said aberration is a banded region in said metal.
21 . The method of claim 4 , wherein said aberration is a banded region substantially parallel to a planar surface of said metal.
22 . The method of claim 4 , wherein said aberration is inconsistent in grain orientation with a predominant grain orientation of said metal.
23 - 24 . (canceled)
25 . The method of claim 4 , wherein detection of aberrations in said metal is throughout a volume of said metal.
26 . (canceled)
27 . The method of claim 4 , wherein reflected signal intensity corresponds to variations in crystallographic orientations of said metal.
28 . The method of claim 4 , wherein said pulsed signals are generated by an ultrasonic transducer.
29 . The method of claim 28 , further comprising:
providing an acoustic transmission medium between said ultrasonic transducer and said metal;
selectively moving said ultrasonic transducer with respect to a surface of said metal; and
providing a processor in communication with said transducer for at least collecting transducer data.
30 . The method of claim 29 , further comprising:
inserting a gate signal in said processor corresponding to a potential aberration in said metal;
processing said reflected signals relative to said gate signal; and
analyzing variations of reflected signals in a region of said gate signal in order to determine banding.
31 - 34 . (canceled)
35 . The method of claim 29 , wherein said acoustic transmission medium is a coupling compound between said ultrasonic transducer and said metal.
36 . The method of claim 29 , wherein said acoustic transmission medium is a fluid bath.
37 . The method of claim 29 , further comprising:
mapping received signals to record a pattern of signals.
38 . A device for automatically scanning a metal to detect banding, comprising:
a fluid bath having said metal immersed therein;
an ultrasonic transducer suspended in said fluid bath and spaced apart from said metal, said ultrasonic transducer sending signals into said metal and obtaining reflected signals therefrom;
means for moving said ultrasonic transducer in a scanning pattern over said metal; and
a processor connected to said ultrasonic transducer for operatively collecting and comparing reflected signal data and outputting a readable result.
39 . A device for automatically scanning a metal to detect banding, comprising:
an acoustic transducer operatively positioned with respect to said metal;
means for moving said acoustic transducer in a scanning pattern over said metal; and
a processor connected to said acoustic transducer for collecting and comparing reflected acoustic signal data and outputting a readable result.
40 - 43 . (canceled)
44 . A metal article having a primary texture, wherein said metal article has a percent texture banding area of less than 1% that is inconsistent or non-uniform with respect to the primary texture present in said metal article.
45 . The metal article of claim 44 , wherein said metal article is a BCC metal article.
46 . The metal article of claim 44 , wherein said metal article is a tantalum article, niobium article, or alloys containing tantalum, niobium, or both.
47 . The metal article of claim 46 , wherein said metal article has at least one of the following characteristics:
a) a purity of at least 95%,
b) an average grain size of 150 microns or less.
48 . The metal article of claim 46 , wherein said primary texture is a primary (111) texture.
49 . The metal article of claim 48 , wherein said percent texture banding area is with respect to (100) texture banding.
50 . The metal article of claim 46 , wherein said metal article has a primary mixed (111):(100) texture.
51 . (canceled)
52 . The metal article of claim 46 , wherein said metal article is a sputter target that is bonded to a backing plate.
53 . (canceled)
54 . The metal article of claim 46 , wherein percent banding area is from 0.5 to 0.99%.
55 . (canceled)
56 . The metal article of claim 46 , wherein said percent banding area is from 0.5 to 0.85%.
57 - 58 . (canceled)
59 . The metal article is claim 46 , wherein said tantalum article is a sputter target bonded to a backing plate.