Strengthening temperature resistance

UV exposure (at k < 300 nm) of the AZ resist prior to plasma etching causes polymer cross-linking (167, 168) or decomposition (169) of the resist photosensitizer near the surface. Thus, a hardened shell or case is formed that permits a higher bake temperature without resist flow and also reduces the etch rate due to plasma exposure. Exposure to inert plasma (e.g., N2) causes similar effects (170), possibly because of ion and electron, as well as UV, bombardment of the resist surface. When F-containing discharges are used, fluorination of the resist surface occurs that strengthens the resist (because of the formation of C-F bonds) and minimizes reactivity (171). 

Steels iu the AISI 400 series contain a minimum of 11.5% chromium and usually not more than 2.5% of any other aHoyiag element these steels are either hardenable (martensitic) or nonhardenable, depending principally on chromium content. Whereas these steels resist oxidation up to temperatures as high as 1150°C, they are not particularly strong above 700°C. Steels iu the AISI 300 series contain a minimum of 16% chromium and 6% nickel the relative amounts of these elements are balanced to give an austenitic stmcture. These steels caimot be strengthened by heat treatment, but can be strain-hardened by cold work. 

Glass—PVB laminates become mote rigid with a decrease in temperature, and below —7° C approach the performance of soHd glass. At temperatures above 38°C these laminates ate less rigid and provide improved penetration resistance. Some appHcations utili2e he at-strengthened or tempered glass for... 

Because pure aluminum is n picaUy too soft to be drawn into a fine wine, it is often alloyed with 1° o sihcon or 1° o magnesium to provide a sofid solution-strengthening mechanism. The resistance of Al-1° o Mg wine to fatigue failure and to degradation of ultimate strength after exposure to elevated temperatures is superior to that of Al—1° o Si wine. 

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