Flame hardening applications

The flame-hardening process is used for a wide variety of applications. These include (1) parts that are so large that conventional furnace treatments are impractical or uneconomical, (2) prevention of detrimental treatment of the entire component when only small segments of die part require heat treatment, and (3) use of less costly material to obtain the desired surface properties where alloyed steels would be normally applied. Flame hardening is limited to hardenable steels (wrought or cast) and cast iron. Typical hardnesses obtained for the flame-hardened grades depend on the quench media (Table 1). The practical level of minimum surface hardness attainable with water quenching for various carbon contents is shown in Fig. 1. 

The composition of an epoxide moulding material will greatly depend on the specific application, and this has been discussed at length. ". The resin may be of the epoxide novolac type and there will also be present hardeners, fillers (such as silica), a silane coupling agent, pigment, flame retardant and a wax release agent. 

The major commercial alternative to DOPO and its derivatives for reactively flame retarding epoxy resins, especially for electronic applications, is an oligo(l,3-phenylene methylphosphonate) (Structure 5.18) marketed by Supresta under the tradename Fyrol PMP. Fyrol PMP has a functionality higher than that of DOPO and can be used either as a hardener (curing agent) or be precondensed with an epoxy. 

An extensive test program using 3 detectors (UV, IR,and Visible) simultaneously with T different flame sources,indicated that thie UV detectors were more respbnsive in most cases. Two distinctly different type d eluge systems will be discussed as applicable to munition processes. One deals with a "hardened ... 

Tetrabromophthalic anhydride. Flame retardant in production of unsaturated polyester resins and rigid PU polyols co-hardener for epoxy resins cost efficient additive for latex emulsions derivatives used as flame retardants in diverse applications (wire coating, and wool, etc.). Crystals mp = 279-281 insoluble in H2O. Ethyl Corp. Great Lakes Firm Chem. 

Although epoxy resin and hardener may be used in unmodified form in adhesive systems, most systems will consist of components that have been modified by incorporation of various additives to achieve specific effects. Formulators will add catalysts or blend hardeners to obtain a specific usable life of the mix and to control the curing temperature. Reactive diluents may be added to modify viscosity or flexibility. Fillers impart improved compression strength and reduce shrinkage and cost. Solvents may be used to reduce viscosity or improve adhesion. Various additives may be added, usually at a low percentage, to reduce aeration, improve adhesion to difficult surfaces, or minimize settlement of fillers. Depending on the application, particular properties such as flame retardency. 

NEC has investigated a benzoguanidine-modified phenolic novolac polymer as a multirole hardener and flame retardant in epoxy polymers for electronic applications. 

Half of all the antimony consumption in the United States is used to make flame retardants used in rubber, plastics, coatings, and so on. Another large application for antimony is to form an alloy with lead, to harden the lead for use in car batteries. 

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