CA1089798A - Transparent article and method of making the same - Google Patents
Transparent article and method of making the sameInfo
- Publication number
- CA1089798A CA1089798A CA286,046A CA286046A CA1089798A CA 1089798 A CA1089798 A CA 1089798A CA 286046 A CA286046 A CA 286046A CA 1089798 A CA1089798 A CA 1089798A
- Authority
- CA
- Canada
- Prior art keywords
- chromium
- continuous surface
- chromium silicide
- glass
- smooth continuous
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Landscapes
- Physical Vapour Deposition (AREA)
Abstract
ABSTRACT
A transparent article having improved abrasion resistance, and method of making the same, which comprises a body of transparent glassy siliceous material having a smooth continuous surface and a continuous film of chromium silicide sputter-coated on said continuous surface to a thickness of from about 200 to 1,000 .ANG..
A transparent article having improved abrasion resistance, and method of making the same, which comprises a body of transparent glassy siliceous material having a smooth continuous surface and a continuous film of chromium silicide sputter-coated on said continuous surface to a thickness of from about 200 to 1,000 .ANG..
Description
3~ 7~
~ SP~CIFICATION
',;
The presen~ invention relates to transparent articles having improved abrasion resistance and to a method of prod-ucing such articles.
The architectural trend toward using more glass in commercial buildings has been enhanced by the availability of special coated and tinted glasses which not only ~erve an aesthetic purpose but also are functional. The most signi-ficant advantages of the special glasses are in the area of air conditioning. Since it generally costs from three to six times more to cool a building one degree than to heat it by the same amount (depending on the amount of glass used), the use of an exterior glass which will reduce the amount of solar _2~
.
radiation entering a building can provide substantial 5aving~
since less air conditioning equipment i~ required and its operation is less costly The special glasses are al~o used in other areas where low heat transmittance is required, i,e~, automobile wlndows and oven windows.
Over the past decade the market for colored and reflective glass has grown significantly~ The colored glass involYed is basically of two types -- tinted and coated.
.... .
Tinted glass i5 generally made by adding selective metals such as iron, cobalt, and nickel to the molten glass during product-ion. This method of producing colored glass is time consuming and wasteful in that when a different color of glass is des-ired, a four or five-day run of glass must be discarded while ... .
the change is made and the new batch ~tabilized. Also, large qua~tities of different colors and types of glass must be inventoried. In addition, although tinted glass does reduce glare, it also absorbs heat (including ~olar radiation) and the absorbed heat is re-radiated from both sides of the glass.
Therefore, a ~reater amount of heat is allowed to pass through the glass than with coated glass.
Coated or reflective glass is provided with a thin .... .
film of a reflective substance on one of its surfaces. The thin film reflects the solar radiation much more effectively ~ than tinted glass since the glass does not absorb the radiat-; ion. Among the materials presently employed for this purpose chromium which can be deposited on glass sheets either by thermal deposition or by the sputter-coating technique.
However, it has been found that pure chromium coatings, while : used with considerable success, are not wholly satisfactory ~n all case~ in that they are susceptible to being marred or .,~ - .
'.~
s ..
, damaged when exposed over a period of time to varying atmos-pheric conditions, or when subjec~ed ~o repeated cleaning or rough handling, Efforts have been made to overcome this condition by overlaying the cbromium ~ilm with a protective coating of a siliceous material, such as Pyrex glass, but thi~ has not proven entirely successful.
It is thererore the primary objective of this invent-ion to 1mprove the abrasion resistance of sputtered coatings on ~lass sheets, . .
- More particularly, it is the purpose of this invent-ion to provide a transparent coating for glass sheets or plates, deposited thereon by sputter-coating, and which possesse9 greater resistance to surface abrasion than relatively pure chromium coatings, A typic~l article according to the present invention comprises a body of transparent glassy siliceous material having a smooth continuous surface, and a continuous abrasion reslstant transparent reflective film of chromium silicide , adhered to said smooth continuous surface, said chromium silicide film consisting essentially of chromium and silicon.
The chromiu~ silicide film is preferably of a thickness of .;~ O
from about 200 to 1,000 A.
m e transparent bodies ~f primary concern are archit-ectural glass, although other uses are possible, such as vehicle windows and oven wlndows. The glassy siliceous material is preferably conventional silicate glass, including window glass, plate glass and float glass, although any ofthe conventional or special purpose glasses may be employed as long as they are transparent.
In preparing glass products according to this invent-s ion, t~e bod~ of transparent glassy siliceous material is first (*) Trademark :; ~
.' ,.
~.~3t~ 8 cleaned by a conventional washing operation and then placedin a deposition chamber containing an inert gas~ The gas in the chamber is preferably maintained at a pressure of from 5 to 50 microns, At pre3sures below 5 microns the rate of deposition during coating is insu~fic~ent for most purpose and there is increased danger of surface con~aminatîon, At pressures above 50 microns the efficiency of the process is significantly reduced. me glass body is preferably heated to a temperature of about 250C, prior to processing.
- The smooth continuous surface is usually ion bomb-arded within the chamber to finally clean and prepare the surface for receiving the coating~ This is generally done by the off-sputtering or reverse sputtering technique which is commonly known, Typically, the sputter-coating time is about twenty minutes at a power density of 0.1 to 1,0-watt/cm2~
~ith certain types of substrates and certain washing or clean-ing processes (prior to insertion in the chamber), the sputter-cleaning step may be unnecessary, The clean, smooth sur~ace i9 then sputter-coated with a continuous film of chromium silicide until a uniform coating -of the desired thickness i9 obtained, Typical sputtering con-ditions are 5,000 volts potential on the target (coating mater-ial) and a resulting current density of 0,5 to 1,0 ma/cm2 for a time period of 0,2 to several minutes depending on the thick-ness of coating desired, The target usually consists of a relatively thin rectangular metal plate having a layer of the coating material to be sputtered applied to one surface thereof, The metal plate ordinarily constitutes the bottom wall of a hollow cathode which is formed with a chamber through which a cooling .
~ ~ -5-,,~
,~ ~ , . .,: .
t~:3~
medium, such as w~ter, is circulated, The cathode is posit-ioned in the deposltion chamber clo5ely adjacent the top thereof, with the glass ~heet to be coated supported horizont-ally therebeneath to receive the chromium silicide upon the upper surface thereof, As is well known, chromium forms several silicides, including Cr3 Sil Cr2 Si, Cr Si and Cr Si2. Also that silicon forms a solid solution of silicon in chromium and can dissolve up to seven and one-half per cent of the silicon, The compos-ition of the silicides are as follows:
Silicide wt/o Silicon Cr3 Si 15 Cr2 ~i 21 r Si 35 Cr Si2 52 The silicided-chromium material used for forming the sputtered films of this invention is preferably in the lower part of the range of composition i,e, about six to fifteen wt!o silicon, This is preferred in order ~o retain properties, ~uch as reflectance and absorbance substantially si~ilar to that of pure chnomium, while still providing a hard abrasion . resistant coating, The corrosion resistance in a normal atmos-phere is similar for both the chromium silicide and the relat-ively pure chromium currently being used, For the preparation of sputtered silicide chromium films on glass according to the present invention, a sputter-ing target was prepared by reacting silicon with electrolytic ¢hromium, This was accomplished as outlined below;
~ I. A 12 x 12 x 1/~ inch sheet of mild 3teel was : electroplated with chromium on one surface as usual to form a chromium sputtering target, II, Silicon powder (-325 mesh~ was sprinkled on ; -6-.
~ 3~ ~
the electroplated surface to a depth o~ -about 1/~ inch, III. The target wi~h the silicon powder was heated in a pure argon atmosphere at 1400F, for 12 hoursO Thiq caused some of the silicon to dissolve in the chromlum to form some - chromium silicide.
IV, The excess residual unreacted silicon powder was brushed from the silicide chromium target.
The above method will result in a target consisting of a solid solution of silicon in chromium along with some chromium silicide (Cr3 Si).
The target was then used for the deposition of silicided chromium films onto 10 x 10 x 1/~ inch sheets of float (soda-lime-silica) glass by the sputtering process above described, As shown by the data given in the following Table I, the silicided chromium films have abrasion resistance significantly superior to those of unsilicided chromium. The abrasion resistance of the sputtered films was measured with a Tabor Abraser with 1000-g wei~hts and a CS-lOF wheel.
~.
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o ~ ~ ~
O ~ ~ ~ ~ ~
00000~00 H
C~
~:n ~o ~3 ~J H
aO ~
~OOOO~`~DO H(~ ~ l ~ P
0~ 0 ~3 ~ D
C~ ~ O
W ~ ''~
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:
The data given in Table I above is correlated with the graph shown in the accompanying drawing wherein line 10 represents the commercial sputtered coatings of substantially pure chromium and line 11 the sputtered chromium silicide coatings of this invention~ As will be seen, the chromium silicide coatings possessed substantially greater resistance to abrasion than the sputtered unsilicided chromium coatings of equal thickness. Also that the superiority of the chrom-ium silicide coatings over the unsilicided chromium coatings increased with increased coating thickness. For example, it required 975 abrasion cycles to remove a silicided chromium coating of a thickness of 615 ~ as against 300 cycles for an unsilicided chromium coating of the same thickness. On the other hand, it required 1300 cycles to remove a chromium silicide coating of a thickness of 9~0 A as against 450 cycles for an unsilicided chromium coating of equal thickness.
, .
,..
~.
{
, . .
' ' _9_ ,:
, .
., , . . ~ .
.. . .
~ SP~CIFICATION
',;
The presen~ invention relates to transparent articles having improved abrasion resistance and to a method of prod-ucing such articles.
The architectural trend toward using more glass in commercial buildings has been enhanced by the availability of special coated and tinted glasses which not only ~erve an aesthetic purpose but also are functional. The most signi-ficant advantages of the special glasses are in the area of air conditioning. Since it generally costs from three to six times more to cool a building one degree than to heat it by the same amount (depending on the amount of glass used), the use of an exterior glass which will reduce the amount of solar _2~
.
radiation entering a building can provide substantial 5aving~
since less air conditioning equipment i~ required and its operation is less costly The special glasses are al~o used in other areas where low heat transmittance is required, i,e~, automobile wlndows and oven windows.
Over the past decade the market for colored and reflective glass has grown significantly~ The colored glass involYed is basically of two types -- tinted and coated.
.... .
Tinted glass i5 generally made by adding selective metals such as iron, cobalt, and nickel to the molten glass during product-ion. This method of producing colored glass is time consuming and wasteful in that when a different color of glass is des-ired, a four or five-day run of glass must be discarded while ... .
the change is made and the new batch ~tabilized. Also, large qua~tities of different colors and types of glass must be inventoried. In addition, although tinted glass does reduce glare, it also absorbs heat (including ~olar radiation) and the absorbed heat is re-radiated from both sides of the glass.
Therefore, a ~reater amount of heat is allowed to pass through the glass than with coated glass.
Coated or reflective glass is provided with a thin .... .
film of a reflective substance on one of its surfaces. The thin film reflects the solar radiation much more effectively ~ than tinted glass since the glass does not absorb the radiat-; ion. Among the materials presently employed for this purpose chromium which can be deposited on glass sheets either by thermal deposition or by the sputter-coating technique.
However, it has been found that pure chromium coatings, while : used with considerable success, are not wholly satisfactory ~n all case~ in that they are susceptible to being marred or .,~ - .
'.~
s ..
, damaged when exposed over a period of time to varying atmos-pheric conditions, or when subjec~ed ~o repeated cleaning or rough handling, Efforts have been made to overcome this condition by overlaying the cbromium ~ilm with a protective coating of a siliceous material, such as Pyrex glass, but thi~ has not proven entirely successful.
It is thererore the primary objective of this invent-ion to 1mprove the abrasion resistance of sputtered coatings on ~lass sheets, . .
- More particularly, it is the purpose of this invent-ion to provide a transparent coating for glass sheets or plates, deposited thereon by sputter-coating, and which possesse9 greater resistance to surface abrasion than relatively pure chromium coatings, A typic~l article according to the present invention comprises a body of transparent glassy siliceous material having a smooth continuous surface, and a continuous abrasion reslstant transparent reflective film of chromium silicide , adhered to said smooth continuous surface, said chromium silicide film consisting essentially of chromium and silicon.
The chromiu~ silicide film is preferably of a thickness of .;~ O
from about 200 to 1,000 A.
m e transparent bodies ~f primary concern are archit-ectural glass, although other uses are possible, such as vehicle windows and oven wlndows. The glassy siliceous material is preferably conventional silicate glass, including window glass, plate glass and float glass, although any ofthe conventional or special purpose glasses may be employed as long as they are transparent.
In preparing glass products according to this invent-s ion, t~e bod~ of transparent glassy siliceous material is first (*) Trademark :; ~
.' ,.
~.~3t~ 8 cleaned by a conventional washing operation and then placedin a deposition chamber containing an inert gas~ The gas in the chamber is preferably maintained at a pressure of from 5 to 50 microns, At pre3sures below 5 microns the rate of deposition during coating is insu~fic~ent for most purpose and there is increased danger of surface con~aminatîon, At pressures above 50 microns the efficiency of the process is significantly reduced. me glass body is preferably heated to a temperature of about 250C, prior to processing.
- The smooth continuous surface is usually ion bomb-arded within the chamber to finally clean and prepare the surface for receiving the coating~ This is generally done by the off-sputtering or reverse sputtering technique which is commonly known, Typically, the sputter-coating time is about twenty minutes at a power density of 0.1 to 1,0-watt/cm2~
~ith certain types of substrates and certain washing or clean-ing processes (prior to insertion in the chamber), the sputter-cleaning step may be unnecessary, The clean, smooth sur~ace i9 then sputter-coated with a continuous film of chromium silicide until a uniform coating -of the desired thickness i9 obtained, Typical sputtering con-ditions are 5,000 volts potential on the target (coating mater-ial) and a resulting current density of 0,5 to 1,0 ma/cm2 for a time period of 0,2 to several minutes depending on the thick-ness of coating desired, The target usually consists of a relatively thin rectangular metal plate having a layer of the coating material to be sputtered applied to one surface thereof, The metal plate ordinarily constitutes the bottom wall of a hollow cathode which is formed with a chamber through which a cooling .
~ ~ -5-,,~
,~ ~ , . .,: .
t~:3~
medium, such as w~ter, is circulated, The cathode is posit-ioned in the deposltion chamber clo5ely adjacent the top thereof, with the glass ~heet to be coated supported horizont-ally therebeneath to receive the chromium silicide upon the upper surface thereof, As is well known, chromium forms several silicides, including Cr3 Sil Cr2 Si, Cr Si and Cr Si2. Also that silicon forms a solid solution of silicon in chromium and can dissolve up to seven and one-half per cent of the silicon, The compos-ition of the silicides are as follows:
Silicide wt/o Silicon Cr3 Si 15 Cr2 ~i 21 r Si 35 Cr Si2 52 The silicided-chromium material used for forming the sputtered films of this invention is preferably in the lower part of the range of composition i,e, about six to fifteen wt!o silicon, This is preferred in order ~o retain properties, ~uch as reflectance and absorbance substantially si~ilar to that of pure chnomium, while still providing a hard abrasion . resistant coating, The corrosion resistance in a normal atmos-phere is similar for both the chromium silicide and the relat-ively pure chromium currently being used, For the preparation of sputtered silicide chromium films on glass according to the present invention, a sputter-ing target was prepared by reacting silicon with electrolytic ¢hromium, This was accomplished as outlined below;
~ I. A 12 x 12 x 1/~ inch sheet of mild 3teel was : electroplated with chromium on one surface as usual to form a chromium sputtering target, II, Silicon powder (-325 mesh~ was sprinkled on ; -6-.
~ 3~ ~
the electroplated surface to a depth o~ -about 1/~ inch, III. The target wi~h the silicon powder was heated in a pure argon atmosphere at 1400F, for 12 hoursO Thiq caused some of the silicon to dissolve in the chromlum to form some - chromium silicide.
IV, The excess residual unreacted silicon powder was brushed from the silicide chromium target.
The above method will result in a target consisting of a solid solution of silicon in chromium along with some chromium silicide (Cr3 Si).
The target was then used for the deposition of silicided chromium films onto 10 x 10 x 1/~ inch sheets of float (soda-lime-silica) glass by the sputtering process above described, As shown by the data given in the following Table I, the silicided chromium films have abrasion resistance significantly superior to those of unsilicided chromium. The abrasion resistance of the sputtered films was measured with a Tabor Abraser with 1000-g wei~hts and a CS-lOF wheel.
~.
-' o )~
o ~ ~ ~
O ~ ~ ~ ~ ~
00000~00 H
C~
~:n ~o ~3 ~J H
aO ~
~OOOO~`~DO H(~ ~ l ~ P
0~ 0 ~3 ~ D
C~ ~ O
W ~ ''~
o~noooooo U~
~ C
.~ .
:
The data given in Table I above is correlated with the graph shown in the accompanying drawing wherein line 10 represents the commercial sputtered coatings of substantially pure chromium and line 11 the sputtered chromium silicide coatings of this invention~ As will be seen, the chromium silicide coatings possessed substantially greater resistance to abrasion than the sputtered unsilicided chromium coatings of equal thickness. Also that the superiority of the chrom-ium silicide coatings over the unsilicided chromium coatings increased with increased coating thickness. For example, it required 975 abrasion cycles to remove a silicided chromium coating of a thickness of 615 ~ as against 300 cycles for an unsilicided chromium coating of the same thickness. On the other hand, it required 1300 cycles to remove a chromium silicide coating of a thickness of 9~0 A as against 450 cycles for an unsilicided chromium coating of equal thickness.
, .
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~.
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, . .
' ' _9_ ,:
, .
., , . . ~ .
.. . .
Claims (9)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An article of manufacture, a transparent glazing element comprising a transparent sheet of glass having a smooth continuous surface, and a continuous abrasion resistant transparent reflective film of chromium silicide adhered to said smooth continuous surface, said chromium silicide film consisting essentially of chromium and silicon.
2. An article of manufacture as claimed in claim 1, in which said chromium silicide film is of a thickness of from about 200 to 1,000 Angstroms.
3. The method of making a transparent glazing element comprising providing a transparent sheet of glass having a smooth continuous surface, and sputter-coating on said smooth continuous surface a continuous abrasion resistant transparent reflective film of chromium silicide consisting essentially of chromium and silicon.
4. The method as claimed in claim 3, wherein the film of chromium silicide is of a thickness of from about 200 to 1,000 Angstroms.
5. The method as claimed in claim 3, wherein the chromium silicide is sputter-coated on the smooth continuous surface of the glass sheet in a low pressure atmosphere containing an inert gas.
6. The method as claimed in claim 4, wherein the chromium silicide is sputter-coated on the smooth continuous surface of the glass sheet in a low pressure atmosphere containing an inert gas.
7. The method as claimed in claim 5, wherein the sputter-coating involves ion bombarding a target of chromium silicide in a low-pressure gaseous atmosphere to cause atomic particles of the chromium silicide to be dislodged and deposited on the smooth continuous surface of the glass sheet.
8. The method as claimed in claim 6, wherein the sputter-coating involvesion bombarding a target of chromium silicide in a low-pressure gaseous atmosphere to cause atomic particles of the chromium silicide to be dislodged and deposited on the smooth continuous surface of the glass sheet.
9. In the method of making a transparent glazing element comprising a transparent sheet of glass having a smooth continuous surface and a continuous abrasion resistant reflective film adhered to said smooth continuous surface, the improvement which comprises providing a sputtering target of chromium silicide consisting essentially of chromium and silicon, and sputtering said chromium silicide from said target in a low-pressure atmosphere containing an inert gas onto said smooth continuous surface of the glass sheet to form a transparent film having a thickness of from about 200 to 1,000 Angstroms.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA286,046A CA1089798A (en) | 1977-09-02 | 1977-09-02 | Transparent article and method of making the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA286,046A CA1089798A (en) | 1977-09-02 | 1977-09-02 | Transparent article and method of making the same |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1089798A true CA1089798A (en) | 1980-11-18 |
Family
ID=4109456
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA286,046A Expired CA1089798A (en) | 1977-09-02 | 1977-09-02 | Transparent article and method of making the same |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1089798A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114651083A (en) * | 2019-11-07 | 2022-06-21 | 欧瑞康表面处理解决方案股份公司普费菲孔 | Method for producing coating |
-
1977
- 1977-09-02 CA CA286,046A patent/CA1089798A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114651083A (en) * | 2019-11-07 | 2022-06-21 | 欧瑞康表面处理解决方案股份公司普费菲孔 | Method for producing coating |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |