An optical glass includes La.sup.3+, Zn.sup.2+, Nb.sup.5+, and Ti.sup.4+ as a cation configuring glass. La.sup.3+, Zn.sup.2+, Nb.sup.5+, and Ti.sup.4+ which satisfy 10 cat %≤La.sup.3+≤20 cat %, 10 cat %≤Zn.sup.2+≤60 cat %, 20 cat %≤Nb.sup.5+≤60 cat %, and 0 cat %≤Ti.sup.4+≤40 cat % expressed by cation %.

Disclosed are coatings made of inorganic materials on molds for glass molding, particularly, a graded coating of element diffusion inhibition and adhesion resistance on molds for glass molding. The graded coating includes a Cr adhesion layer which is bonded with a substrate, a CrN intermediate layer and a Cr.sub.xW.sub.yN.sub.(1-x-y) surface layer, where 0.15<x<0.4, and 0.2≤y<0.45. The graded coating has excellent crack growth suppression and adhesion resistance.

An amorphous alloy contains Ni and Nb and has a composition including at least one of: a composition containing Nb with a content in the range of 35.6 atomic % to 75.1 atomic %, Ir with a content in the range of 7.2 atomic % to 52.3 atomic %, and Ni with a content in the range of 4.0 atomic % to 48.5 atomic %; a composition containing Nb with a content in the range of 19.6 atomic % to 80.9 atomic %, Re with a content in the range of 7.4 atomic % to 59.2 atomic %, and Ni with a content in the range of 4.1 atomic % to 56.9 atomic %; and a composition containing Nb with a content in the range of 7.5 atomic % to 52.9 atomic %, W with a content in the range of 16.4 atomic % to 47.0 atomic %, and Ni with a content in the range of 22.0 atomic % to 53.3 atomic %.

Provided is an optical glass containing glass-forming cations, the optical glass satisfying, expressed in cation percent, 10 cat %B.sup.3+50 cat %, 15 cat %La.sup.3+35 cat %, 20 cat %Nb.sup.5+50 cat %, and 15 cat %Ti.sup.4+25 cat %.

An amorphous alloy contains Ni and Nb and has a composition including at least one of: a composition containing Nb with a content in the range of 35.6 atomic % to 75.1 atomic %, Ir with a content in the range of 7.2 atomic % to 52.3 atomic %, and Ni with a content in the range of 4.0 atomic % to 48.5 atomic %; a composition containing Nb with a content in the range of 19.6 atomic % to 80.9 atomic %, Re with a content in the range of 7.4 atomic % to 59.2 atomic %, and Ni with a content in the range of 4.1 atomic % to 56.9 atomic %; and a composition containing Nb with a content in the range of 7.5 atomic % to 52.9 atomic %, W with a content in the range of 16.4 atomic % to 47.0 atomic %, and Ni with a content in the range of 22.0 atomic % to 53.3 atomic %.

Disclosed are coatings made of inorganic materials on molds for glass molding, particularly, a graded coating of element diffusion inhibition and adhesion resistance on molds for glass molding. The graded coating includes a Cr adhesion layer which is bonded with a substrate, a CrN intermediate layer and a Cr.sub.xW.sub.yN.sub.(1-x-y) surface layer, where 0.15<x<0.4, and 0.2y<0.45. The graded coating has excellent crack growth suppression and adhesion resistance.

Precision glass molds are described, which are formed by coating a mold made from high purity, fme grain sized graphite, with a coating including titanium. In various implementations, the titanium coating is overcoated with yttria (Y.sub.2O.sub.3) to provide a high precision glass mold of superior performance character. The resultant glass molds can be used to form glass articles having a highly smooth finish, for high precision applications such as consumer electronic device applications, medical instruments, and optical devices. The use of high purity, fme grain size graphite allows molds to be machined at low cost, thereby eliminating the need to fabricate a metal mold that must be coated with multiple layers including metal diffusion barrier layers to meet operational requirements for such precision applications.

An amorphous alloy contains Ni and Nb and has a composition including at least one of: a composition containing Nb with a content in the range of 35.6 atomic % to 75.1 atomic %, Ir with a content in the range of 7.2 atomic % to 52.3 atomic %, and Ni with a content in the range of 4.0 atomic % to 48.5 atomic %; a composition containing Nb with a content in the range of 19.6 atomic % to 80.9 atomic %, Re with a content in the range of 7.4 atomic % to 59.2 atomic %, and Ni with a content in the range of 4.1 atomic % to 56.9 atomic %; and a composition containing Nb with a content in the range of 7.5 atomic % to 52.9 atomic %, W with a content in the range of 16.4 atomic % to 47.0 atomic %, and Ni with a content in the range of 22.0 atomic % to 53.3 atomic %.

An optical glass includes La.sup.3+, Zn.sup.2+, Nb.sup.5+, and Ti.sup.4+ as a cation configuring glass. La.sup.3+, Zn.sup.2+, Nb.sup.5+, and Ti.sup.4+ which satisfy 10 cat %La.sup.3+20 cat %, 10 cat %Zn.sup.2+60 cat %, 20 cat %Nb.sup.5+60 cat %, and 0 cat %Ti.sup.4+40 cat % expressed by cation %.

Precision glass molds are described, which are formed by coating a mold made from high purity, fine grain sized graphite, with a coating including titanium. In various implementations, the titanium coating is overcoated with yttria (Y.sub.2O.sub.3) to provide a high precision glass mold of superior performance character. The resultant glass molds can be used to form glass articles having a highly smooth finish, for high precision applications such as consumer electronic device applications, medical instruments, and optical devices. The use of high purity, fine grain size graphite allows molds to be machined at low cost, thereby eliminating the need to fabricate a metal mold that must be coated with multiple layers including metal diffusion barrier layers to meet operational requirements for such precision applications.