Hardness of dislocations, a particular metal's hardness can be controlled. Although seemingly counter-intuitive, as the density of dislocations increases, there are more intersections created and consequently more anchor points. Similarly, as more interstitial atoms are added, more pinning points that impede the movements of dislocations are formed. As a result, the more anchor points added, the harder the material will become. Hardness Hardness is a measure of the resistance to localized plastic deformation induced by either mechanical indentation or abrasion. Some materials (e.g. metals) are harder than others (e.g. plastics, wood). Macroscopic hardness is generally characterized by strong intermolecular bonds, but
Walter Janka exile in Mexico, where together with Paul Merker and Alexander Abusch he founded the "Free Germany" (""Freies Deutschland"") movement. In Mexico he ran the publishing business "El Libro Libre", which also employed the exiled German writer Anna Seghers. In 1946 Janka took on the leadership of the Mexican section of the German Communist party (KPD). After the end of the Second World War Janka returned, in April 1947, to what was Soviet occupation zone, later to become German Democratic Repbulic in 1949. In 1947 he married his long-standing partner, a translator called Charlotte (Lotte) Scholz. The couples' two children, André