This range of alloys is designed for the brazing of difficult parent metals such as cast iron and cemented carbides where the wetting of the brazing alloy on to the parent metal can be difficult.
Wetting is enhanced by the presence of nickel in a brazing alloy. This nickel content also alters the fluidity of the alloy, giving thicker joints which are more able to dissipate higher levels of internal stresses. These internal stresses are caused by the differences in the coefficients of thermal expansion of steel and carbide parent metals and appear as strong compressive forces as the joint cools. Where such stresses reach very high values, especially with brittle grades of carbide the use of Plymetal Z, where a soft central layer of copper will plastically deform and absorb the reduced stresses, should be considered.
M19MN has the additional benefits of been able to wet graphite-containing materials and can be used for brazing difficult parent metals such as grey cast iron.